- replace JustWifi with a custom WiFi module
- re-implemented Core methods that deal with scanning, directly work with the SDK callback
- re-implemented Core method for opmode to avoid dealing with the 2.7.x pseudo modes
- re-implemented Core method for forced-(modem)-sleep (with the intention to merge with OpmodeNull... todo)
- disable reconnect and autoconnect from SDK, avoid unintentionally storing ssid & pass for these and
  make connection routine watch for events instead. timeout is implemented as a local timer
- do not store runtime data that can be retrieved via SDK calls
- settings are loaded only when starting AP or STA, networks are no longer kept in memory
- settings STA ssidN must be unique
- remove char buffer from the event callback
- trigger station-disconnected event when actually disconnected, not when connecting or explicitly requesting it
- generic rssi sorting method for initial connection, do rssi checks while connected to find a better network

Drop (temporarily?) wps and smartconfig. Both are implementable with the new approach,
but come with some weird expectations from the SDK side (no extra heap with wps, broadcasting plain-text
passphrase with smartconfig, storing station config implicitly, etc.).

Both are sort-of fixed with RTOS SDK, but it is still a big question of whether to support them at all in the current state.

- support 32 byte hostname / ssid
- support 64 byte passphrase
- slightly reduce amount of memory allocations
- tweak initialization paths to call persistent(false) as early as possible

see 69c65a6a40 (commitcomment-42008295)
Because of the way DHCP is integrated into the Core logic, we need to
call wifi_softap_add_dhcps_lease(...) inbetween WiFi.softApConfig(...) and WiFi.softAp(...)

Remember MAC for the current IP sequence number
(e.g. lease 0 -> xxx.xxx.xxx.2, lease 1 -> xxx.xxx.xxx.3 and etc.)

~500 bytes of code

- replace `apmode` with `wifiApMode`
- deprecate `WIFI_FALLBACK_APMODE` in favour of the AP mode setting
- allow to set custom SSID and passphrase for the softAP via `wifiApSsid` & `wifiApPass`
- identifier fallback for hostname

Change the underlying command line handling:
- switch to a custom parser, inspired by redis / sds
- update terminalRegisterCommand signature, pass only bare minimum
- clean-up `help` & `commands`. update settings `set`, `get` and `del`
- allow our custom test suite to run command-line tests
- clean-up Stream IO to allow us to print large things into debug stream (for example, `eeprom.dump`)
- send parsing errors to the debug log

As a proof of concept, introduce `TERMINAL_MQTT_SUPPORT` and `TERMINAL_WEB_API_SUPPORT`
- MQTT subscribes to the `<root>/cmd/set` and sends response to the `<root>/cmd`. We can't output too much, as we don't have any large-send API.
- Web API listens to the `/api/cmd?apikey=...&line=...` (or PUT, params inside the body). This one is intended as a possible replacement of the `API_SUPPORT`. Internals introduce a 'task' around the AsyncWebServerRequest object that will simulate what WiFiClient does and push data into it continuously, switching between CONT and SYS.

Both are experimental. We only accept a single command and not every command is updated to use Print `ctx.output` object. We are also somewhat limited by the Print / Stream overall, perhaps I am overestimating the usefulness of Arduino compatibility to such an extent :)
Web API handler can also sometimes show only part of the result, whenever the command tries to yield() by itself waiting for something. Perhaps we would need to create a custom request handler for that specific use-case.

* emon: configure ratios without reboot

* settings: serialize() support

* debug: use vsnprintf from newlib, not from sdk

* settings/experimental: show defaults via `get`

* emon: override base methods, fix defaults

* sensor/emon: expose internal index calculation

- refactor configuration to use the correct index when accessing indexed
  sensor methods. store index value on magnitude, refactor loops to
  accomodate this new functionality
- rename slot(index) -> description(index), since we use 'slot' as
  numeric value

- general conversion from .ino modules into a separate .cpp files
- clean-up internal headers, place libraries into .h. guard .cpp with _SUPPORT flags 
- fix some instances of shared variables instead of public methods
- tweak build system to still build a single source file via os environment variable ESPURNA_BUILD_SINGLE_SOURCE

* experimental: refactor get/set/del/hasSetting

* sensors

* lights

* cleaup

* r

* tuya

* fixup! sensors

* fixup! tuya

* header defaults types

* fix lights

* setup already checks for max

* helper for flashstring

* fix overload

* oops

* refactor includes

* warnings

* test with migrate

* add ids in a separate file

* cleanup

rev: crash

rev: domoticz

rev: encoder

rev: loopdelay

rev: hass

rev: i2c

rev2: hass

rev: mqtt

rev: rfm69

rev: relay

rev: rpn

rev: settings setup

rev: hb settings

rev: telnet preprocessor fix

rev: settings wrap

rev: tspk bool style

rev: wifi types

rev: util hb

rev: settings

fixup! rev: settings

* rev: cleanup wifi injections based on new getters

* hasSetting now can return true for empty key

* show hardcoded network in web

* oops

* fix ws referencing wrong index

* ensure empty strings are written

* c/p

* use experimental schema style for payload, mark network as not deletable

* allow to customize converter

* shorter syntax, try using with wifi

* use proper #if syntax to handle definitions that are missing

* fixup ota sc checks getter, cast schEnabled to bool

* add utils header to sensors

* Test: check core feature build

* order

* add missing

* web: re-add wifi scan action, send as json array

* ws: forcibly inline send functions

* use indexed getsetting
* store defaults in progmem

* test: etharp_gratuitous

* proper checks before calling etharp_gratuitous, move includes

* disable at runtime

* ms values

* reload

* debug

* reword

* filter by ifnum instead of checking for AP mode

* drop station_if check

2.3.0/lwip1 builds netif->num increments on for each sta or ap
lwip2 keeps those constant, but that seems like a implementation detail
might break in the future anyways...

* Stop updating SoftAP SSID and password when changing hostname and password via WebUI / settings `reload`:
https://gitter.im/tinkerman-cat/espurna?at=5d65418f49ac051923be1f06
* Show real ssid and psk values from the current sdk configuration instead of using getSetting
* `WIFI.STA` command

- update every dynamicjsonbuffer with fixed size constructor argument
- change to ws callback registration to use a class builder (just cosmetic)
- test multiple ws data callbacks for each module
- remove some of the static strings in favour of ws data callback
- improve sensor ws callback data size, remove duplicated strings
- use static buffer in wsDebugSend
- postpone wsSend until loop, implement wsPost to allow other modules to queue message callbacks. remove Ticker based ws callbacks for data
- update WebUI files

* Make compilation more flexible allowing to define in custom.h your own variation to devices and define four wifi networks

* Implement suggestion from Max Prokhorov, it's simpler and cleaner

* Change a #elif by #else

* Move ESPurna Core comment

This reverts commit 7ad0e3a02b.

This is the Info main menu (aka directory node).
A few useful Info commands:

  'q' quits;
  '?' lists all Info commands;
  'h' starts the Info tutorial;
  'mTexinfo RET' visits the Texinfo manual, etc.

* Menu:

Basics
* Common options: (coreutils)Common options.
* Coreutils: (coreutils).       Core GNU (file, text, shell) utilities.
* Date input formats: (coreutils)Date input formats.
* Ed: (ed).                     The GNU line editor
* File permissions: (coreutils)File permissions.
                                Access modes.
* Finding files: (find).        Operating on files matching certain criteria.

C++ libraries
* autosprintf: (autosprintf).   Support for printf format strings in C++.

Compression
* Gzip: (gzip).                 General (de)compression of files (lzw).

Development
* SSIP: (ssip).                 Speech Synthesis Interface Protocol.
* Speech Dispatcher: (speech-dispatcher).
                                Speech Dispatcher.
* libffi: (libffi).             Portable foreign-function interface library.

DOS
* Mtools: (mtools).             Mtools: utilities to access DOS disks in Unix.

Editors
* nano: (nano).                 Small and friendly text editor.

General Commands
* Screen: (screen).             Full-screen window manager.

GNU Gettext Utilities
* autopoint: (gettext)autopoint Invocation.
                                Copy gettext infrastructure.
* envsubst: (gettext)envsubst Invocation.
                                Expand environment variables.
* gettextize: (gettext)gettextize Invocation.
                                Prepare a package for gettext.
* gettext: (gettext).           GNU gettext utilities.
* ISO3166: (gettext)Country Codes.
                                ISO 3166 country codes.
* ISO639: (gettext)Language Codes.
                                ISO 639 language codes.
* msgattrib: (gettext)msgattrib Invocation.
                                Select part of a PO file.
* msgcat: (gettext)msgcat Invocation.
                                Combine several PO files.
* msgcmp: (gettext)msgcmp Invocation.
                                Compare a PO file and template.
* msgcomm: (gettext)msgcomm Invocation.
                                Match two PO files.
* msgconv: (gettext)msgconv Invocation.
                                Convert PO file to encoding.
* msgen: (gettext)msgen Invocation.
                                Create an English PO file.
* msgexec: (gettext)msgexec Invocation.
                                Process a PO file.
* msgfilter: (gettext)msgfilter Invocation.
                                Pipe a PO file through a filter.
* msgfmt: (gettext)msgfmt Invocation.
                                Make MO files out of PO files.
* msggrep: (gettext)msggrep Invocation.
                                Select part of a PO file.
* msginit: (gettext)msginit Invocation.
                                Create a fresh PO file.
* msgmerge: (gettext)msgmerge Invocation.
                                Update a PO file from template.
* msgunfmt: (gettext)msgunfmt Invocation.
                                Uncompile MO file into PO file.
* msguniq: (gettext)msguniq Invocation.
                                Unify duplicates for PO file.
* ngettext: (gettext)ngettext Invocation.
                                Translate a message with plural.
* xgettext: (gettext)xgettext Invocation.
                                Extract strings into a PO file.

GNU organization
* Maintaining Findutils: (find-maint).
                                Maintaining GNU findutils

GNU Utilities
* dirmngr-client: (gnupg).      X.509 CRL and OCSP client.
* dirmngr: (gnupg).             X.509 CRL and OCSP server.
* gpg: (gnupg1).                OpenPGP encryption and signing tool (v1).
* gpg-agent: (gnupg).           The secret key daemon.
* gpg2: (gnupg).                OpenPGP encryption and signing tool.
* gpgsm: (gnupg).               S/MIME encryption and signing tool.

Individual utilities
* aclocal-invocation: (automake-1.15)aclocal Invocation.
                                                Generating aclocal.m4.
* arch: (coreutils)arch invocation.             Print machine hardware name.
* automake-invocation: (automake-1.15)automake Invocation.
                                                Generating Makefile.in.
* base32: (coreutils)base32 invocation.         Base32 encode/decode data.
* base64: (coreutils)base64 invocation.         Base64 encode/decode data.
* basename: (coreutils)basename invocation.     Strip directory and suffix.
* bibtex: (web2c)bibtex invocation.             Maintaining bibliographies.
* cat: (coreutils)cat invocation.               Concatenate and write files.
* chcon: (coreutils)chcon invocation.           Change SELinux CTX of files.
* chgrp: (coreutils)chgrp invocation.           Change file groups.
* chmod: (coreutils)chmod invocation.           Change access permissions.
* chown: (coreutils)chown invocation.           Change file owners and groups.
* chroot: (coreutils)chroot invocation.         Specify the root directory.
* cksum: (coreutils)cksum invocation.           Print POSIX CRC checksum.
* cmp: (diffutils)Invoking cmp.                 Compare 2 files byte by byte.
* comm: (coreutils)comm invocation.             Compare sorted files by line.
* cp: (coreutils)cp invocation.                 Copy files.
* csplit: (coreutils)csplit invocation.         Split by context.
* cut: (coreutils)cut invocation.               Print selected parts of lines.
* date: (coreutils)date invocation.             Print/set system date and time.
* dd: (coreutils)dd invocation.                 Copy and convert a file.
* df: (coreutils)df invocation.                 Report file system disk usage.
* diff: (diffutils)Invoking diff.               Compare 2 files line by line.
* diff3: (diffutils)Invoking diff3.             Compare 3 files line by line.
* dir: (coreutils)dir invocation.               List directories briefly.
* dircolors: (coreutils)dircolors invocation.   Color setup for ls.
* dirname: (coreutils)dirname invocation.       Strip last file name component.
* du: (coreutils)du invocation.                 Report on disk usage.
* dvicopy: (web2c)dvicopy invocation.           Virtual font expansion
* dvitomp: (web2c)dvitomp invocation.           DVI to MPX (MetaPost pictures).
* dvitype: (web2c)dvitype invocation.           DVI to human-readable text.
* echo: (coreutils)echo invocation.             Print a line of text.
* env: (coreutils)env invocation.               Modify the environment.
* expand: (coreutils)expand invocation.         Convert tabs to spaces.
* expr: (coreutils)expr invocation.             Evaluate expressions.
* factor: (coreutils)factor invocation.         Print prime factors
* false: (coreutils)false invocation.           Do nothing, unsuccessfully.
* find: (find)Invoking find.                    Finding and acting on files.
* fmt: (coreutils)fmt invocation.               Reformat paragraph text.
* fold: (coreutils)fold invocation.             Wrap long input lines.
* gftodvi: (web2c)gftodvi invocation.           Generic font proofsheets.
* gftopk: (web2c)gftopk invocation.             Generic to packed fonts.
* gftype: (web2c)gftype invocation.             GF to human-readable text.
* groups: (coreutils)groups invocation.         Print group names a user is in.
* gunzip: (gzip)Overview.                       Decompression.
* gzexe: (gzip)Overview.                        Compress executables.
* head: (coreutils)head invocation.             Output the first part of files.
* hostid: (coreutils)hostid invocation.         Print numeric host identifier.
* hostname: (coreutils)hostname invocation.     Print or set system name.
* id: (coreutils)id invocation.                 Print user identity.
* install: (coreutils)install invocation.       Copy files and set attributes.
* join: (coreutils)join invocation.             Join lines on a common field.
* kill: (coreutils)kill invocation.             Send a signal to processes.
* link: (coreutils)link invocation.             Make hard links between files.
* ln: (coreutils)ln invocation.                 Make links between files.
* locate: (find)Invoking locate.                Finding files in a database.
* logname: (coreutils)logname invocation.       Print current login name.
* ls: (coreutils)ls invocation.                 List directory contents.
* md5sum: (coreutils)md5sum invocation.         Print or check MD5 digests.
* mf: (web2c)mf invocation.                     Creating typeface families.
* mft: (web2c)mft invocation.                   Prettyprinting Metafont source.
* mkdir: (coreutils)mkdir invocation.           Create directories.
* mkfifo: (coreutils)mkfifo invocation.         Create FIFOs (named pipes).
* mknod: (coreutils)mknod invocation.           Create special files.
* mktemp: (coreutils)mktemp invocation.         Create temporary files.
* mltex: (web2c)MLTeX.                          Multi-lingual TeX.
* mpost: (web2c)mpost invocation.               Creating technical diagrams.
* mv: (coreutils)mv invocation.                 Rename files.
* nice: (coreutils)nice invocation.             Modify niceness.
* nl: (coreutils)nl invocation.                 Number lines and write files.
* nohup: (coreutils)nohup invocation.           Immunize to hangups.
* nproc: (coreutils)nproc invocation.           Print the number of processors.
* numfmt: (coreutils)numfmt invocation.         Reformat numbers.
* od: (coreutils)od invocation.                 Dump files in octal, etc.
* paste: (coreutils)paste invocation.           Merge lines of files.
* patch: (diffutils)Invoking patch.             Apply a patch to a file.
* patgen: (web2c)patgen invocation.             Creating hyphenation patterns.
* pathchk: (coreutils)pathchk invocation.       Check file name portability.
* pktogf: (web2c)pktogf invocation.             Packed to generic fonts.
* pktype: (web2c)pktype invocation.             PK to human-readable text.
* pltotf: (web2c)pltotf invocation.             Property list to TFM.
* pooltype: (web2c)pooltype invocation.         Display WEB pool files.
* pr: (coreutils)pr invocation.                 Paginate or columnate files.
* printenv: (coreutils)printenv invocation.     Print environment variables.
* printf: (coreutils)printf invocation.         Format and print data.
* ptx: (coreutils)ptx invocation.               Produce permuted indexes.
* pwd: (coreutils)pwd invocation.               Print working directory.
* readlink: (coreutils)readlink invocation.     Print referent of a symlink.
* realpath: (coreutils)realpath invocation.     Print resolved file names.
* rm: (coreutils)rm invocation.                 Remove files.
* rmdir: (coreutils)rmdir invocation.           Remove empty directories.
* runcon: (coreutils)runcon invocation.         Run in specified SELinux CTX.
* sdiff: (diffutils)Invoking sdiff.             Merge 2 files side-by-side.
* seq: (coreutils)seq invocation.               Print numeric sequences
* sha1sum: (coreutils)sha1sum invocation.       Print or check SHA-1 digests.
* sha2: (coreutils)sha2 utilities.              Print or check SHA-2 digests.
* shred: (coreutils)shred invocation.           Remove files more securely.
* shuf: (coreutils)shuf invocation.             Shuffling text files.
* sleep: (coreutils)sleep invocation.           Delay for a specified time.
* sort: (coreutils)sort invocation.             Sort text files.
* split: (coreutils)split invocation.           Split into pieces.
* stat: (coreutils)stat invocation.             Report file(system) status.
* stdbuf: (coreutils)stdbuf invocation.         Modify stdio buffering.
* stty: (coreutils)stty invocation.             Print/change terminal settings.
* sum: (coreutils)sum invocation.               Print traditional checksum.
* sync: (coreutils)sync invocation.             Synchronize memory to disk.
* tac: (coreutils)tac invocation.               Reverse files.
* tail: (coreutils)tail invocation.             Output the last part of files.
* tangle: (web2c)tangle invocation.             WEB to Pascal.
* tee: (coreutils)tee invocation.               Redirect to multiple files.
* test: (coreutils)test invocation.             File/string tests.
* tex: (web2c)tex invocation.                   Typesetting.
* tftopl: (web2c)tftopl invocation.             TFM -> property list.
* time: (time).                                 Run programs and summarize
                                                  system resource usage.
* timeout: (coreutils)timeout invocation.       Run with time limit.
* touch: (coreutils)touch invocation.           Change file timestamps.
* tr: (coreutils)tr invocation.                 Translate characters.
* true: (coreutils)true invocation.             Do nothing, successfully.
* truncate: (coreutils)truncate invocation.     Shrink/extend size of a file.
* tsort: (coreutils)tsort invocation.           Topological sort.
* tty: (coreutils)tty invocation.               Print terminal name.
* uname: (coreutils)uname invocation.           Print system information.
* unexpand: (coreutils)unexpand invocation.     Convert spaces to tabs.
* uniq: (coreutils)uniq invocation.             Uniquify files.
* unlink: (coreutils)unlink invocation.         Removal via unlink(2).
* updatedb: (find)Invoking updatedb.            Building the locate database.
* uptime: (coreutils)uptime invocation.         Print uptime and load.
* users: (coreutils)users invocation.           Print current user names.
* vdir: (coreutils)vdir invocation.             List directories verbosely.
* vftovp: (web2c)vftovp invocation.             Virtual font -> virtual pl.
* vptovf: (web2c)vptovf invocation.             Virtual pl -> virtual font.
* wc: (coreutils)wc invocation.                 Line, word, and byte counts.
* weave: (web2c)weave invocation.               WEB to TeX.
* who: (coreutils)who invocation.               Print who is logged in.
* whoami: (coreutils)whoami invocation.         Print effective user ID.
* xargs: (find)Invoking xargs.                  Operating on many files.
* yes: (coreutils)yes invocation.               Print a string indefinitely.
* zcat: (gzip)Overview.                         Decompression to stdout.
* zdiff: (gzip)Overview.                        Compare compressed files.
* zforce: (gzip)Overview.                       Force .gz extension on files.
* zgrep: (gzip)Overview.                        Search compressed files.
* zmore: (gzip)Overview.                        Decompression output by pages.

Kernel
* GRUB: (grub).                 The GRand Unified Bootloader
* grub-dev: (grub-dev).         The GRand Unified Bootloader Dev
* grub-install: (grub)Invoking grub-install.
                                Install GRUB on your drive
* grub-mkconfig: (grub)Invoking grub-mkconfig.
                                Generate GRUB configuration
* grub-mkpasswd-pbkdf2: (grub)Invoking grub-mkpasswd-pbkdf2.
* grub-mkrelpath: (grub)Invoking grub-mkrelpath.
* grub-mkrescue: (grub)Invoking grub-mkrescue.
                                Make a GRUB rescue image
* grub-mount: (grub)Invoking grub-mount.
                                Mount a file system using GRUB
* grub-probe: (grub)Invoking grub-probe.
                                Probe device information
* grub-script-check: (grub)Invoking grub-script-check.

Libraries
* RLuserman: (rluserman).       The GNU readline library User's Manual.

Man-pages
* Latex2man: (latex2man).       Its Man-Page

Math
* bc: (bc).                     An arbitrary precision calculator language.
* dc: (dc).                     Arbitrary precision RPN "Desktop Calculator".

Network applications
* Wget: (wget).                 Non-interactive network downloader.

Programming
* flex: (flex).                 Fast lexical analyzer generator (lex
                                  replacement).
* gnucash: (gnucash-design).    Design of the GnuCash program

Programming Tools
* Gperf: (gperf).               Perfect Hash Function Generator.

Software development
* Autoconf Archive: (autoconf-archive).
                                A collection of re-usable Autoconf macros.
* Automake: (automake-1.15).    Making GNU standards-compliant Makefiles.

Sound
* SSIP: (ssip).                 Speech Synthesis Interface Protocol.
* Say for Speech Dispatcher: (spd-say).
                                Say.
* Speech Dispatcher: (speech-dispatcher).
                                Speech Dispatcher.

TeX
* DVI-to-PNG: (dvipng).         Translating TeX DVI files to Portable Network
                                  Graphics (PNG).
* DVI-to-Postscript: (dvips).   Translating TeX DVI files to PostScript.
* Eplain: (eplain).             Expanding on plain Tex.
* EpsPDF: (epspdf).             Portable GUI- and command-line EPS/PS/PDF
                                  conversion
* Kpathsea: (kpathsea).         File lookup along search paths.
* LaTeX2e: (latex2e).           Unofficial LaTeX reference manual.
* LaTeX2e-es: (latex2e-es).     Manual de extraoficial de LaTeX.
* Naming TeX fonts: (fontname). Filenames for TeX fonts.
* TL-build: (tlbuild).          TeX Live configuration and development.
* TeX Directories: (tds).       A directory structure for TeX files.
* TeXdraw: (texdraw).           A system for producing PostScript drawings
                                  from TeX.
* Web2c: (web2c).               TeX, Metafont, and companion programs.
* afm2tfm: (dvips)Invoking afm2tfm.
                                Making Type 1 fonts available to TeX.
* dvipng: (dvipng).             A DVI-to-PNG translator.
* dvips: (dvips)Invoking Dvips. DVI-to-PostScript translator.
* kpsewhich: (kpathsea)Invoking kpsewhich.
                                TeX file searching.
* mf2pt1: (mf2pt1).             PostScript Type 1 fonts from Metafont source.
* mktexfmt: (kpathsea)mktex scripts.
                                Format (fmt/base/mem) generation.
* mktexlsr: (kpathsea)Filename database.
                                Update ls-R.
* mktexmf: (kpathsea)mktex scripts.
                                MF source generation.
* mktexpk: (kpathsea)mktex scripts.
                                PK bitmap generation.
* mktextex: (kpathsea)mktex scripts.
                                TeX source generation.
* mktextfm: (kpathsea)mktex scripts.
                                TeX font metric generation.

Text creation and manipulation
* Diffutils: (diffutils).       Comparing and merging files.
* M4: (m4).                     A powerful macro processor.
* grep: (grep).                 Print lines matching a pattern.
* sed: (sed).                   Stream EDitor.   command. Use *  SSID  MODE  CHAN  RATE  SIGNAL  BARS  SECURITY  to get current connections