Specifically, this will break RFM69_SUPPORT on case insensitive
filesystems due to the RFM69.cpp from the RFM69 lib being ignored
when adding ESPurna's rfm69.cpp

* [1/2] use #include for single source

* [2/2] use #include for single source

- 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

- don't depend on TRAVIS environment variables
- depend on CI flag to add release variables
- chmod +x

* base envs

* CI: speed up release process (since we still want some .bin files)

* fixup! CI: speed up release process (since we still want some .bin files)

* release dry run

* fixup! release dry run

* adjust

* fix .bin name

* it works

* minor cleanup for current git

* use pio suggestion about ldscript, reduce build_flags impact

* fix linker

* parse ${vars} instead of ignoring them

* add filtering and override file (sneak peak into tasmota's pio config)

* don't generate secure client (for now)

* formatting

* codacy

* PIO: remove -ota envs, handle OTA condition in extra script
* Tweak ESPURNA_BOARD variable
* Support git and latest in ota script
* Handle ESPURNA_FLAGS too
* Try to handle env and projenv in pylint
* Add deprecation comment about -ota envs
* regen arduino.h

* utils/version: use git description token as version, add memoization

* pio: move extra scripts to a separate directory

* pio: add -DAPP_REVISION=... as local build flag

* Core 2.6.0+ fixes

* fix env -> config, run travis04 job

* don't duplicate free heap in frag data, use single stats struct

* fix dtostrf warnings, bump buffer sizes

* ...and even less words for fragmentation stat

* initial ldscripts refactoring

* add missing menu options

* board for 2.3.0 and 2.4.2

* test with core 2.5.0

* typo

* ...same typo in other boards.local.txt

* generate boards.local.txt from common template

* Depend on file presence instead of platform version

* sdk selection

* Override only relevant entries

* generate ldscripts

* formatting

* unused

* fix section scope

* fix linker script comment and build getting stuck

* py2 compat

platformio from pip still does not support py3

* add TODO for py3

* chmod +x, remove leading newline

* comment with real spiffs size

* fixup! chmod +x, remove leading newline

* regenerate all ldscripts

* Preventive fix of spiffs_end calculation

* update arg parsing

* generate only 2.3.0 and latest

* readme for boards.local.txt

* Update ldscript readme

* unique flash sizes

* fix sub

* line break

* correct way to get framework path

* Alias for _FS_... symbols

* unused 2m1m1s

* bump?

* show travis logs

* ensure latest toolchain for travis

* check platform packages when building

- update file paths: .pioenvs -> .pio/build, .piolibdeps -> .pio/libdeps
- modify envs to use common settings
- enable shared libs in travis and ota scripts