1. Add thermostat to the espurna_modules in progmem.h
2. Add thermostat to webui, gulp, html, js.
3. in general.h MQTT_USE_JSON returned to 0 by default and 1 if thermostat enabled.

* Simply print timestamp for supported destinations
* Update ws destination to support 'prefix' sub-key
* Avoid void casting in telnet module

* send all ws config at once on start
* reduce ws json overhead by creating message buffer manually
* use k:[values] instead of k1:value1, k2:value2 etc. for lists

- Heartbeat mode and interval configuration added to WebUI ADMIN page
- New option HEARTBEAT_REPEAT_STATUS: on device startup full heartbeat information and after HEARTBEAT_INTERVAL only STATUS report.
- Enhanced first heartbeat message - on device startup it will send heartbeat after ntpSynced will be true to get device time.

P.S. Code is tested. Web part is not compiled, and not tested. I hope it will work :)

* Fix energy ratio input for pulse meter sensor

* checkout origin/dev -- webui files

* Telnet auth depends on setting

* use same define suffix as WS_

* add to web

* no initial passwd for core

Show alert if no input on #password page
Do not fail with empty password when on #layout
Fix password selector

Bump npm version installed by travis
Update package-lock for latest npm version
Bump packages versions and clean-up unused
Missing datatables.js images to avoid warnings

* revise first-time-use screen
* generate password (policy applies)
* hide/reveal password text for sta/admin settings
* changed autocomplete='...' for some inputs to avoid completion

* fix webui regexp and input length limits
* explain requirements in webui and headers