* Add "Enable Thermostat" switch

* Add heater/cooler thermostat mode

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.

- 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

* 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

also minor html fixes