- 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

* Works with many different ultrasonic sensor models: HC-SR04, SRF05,
  SRF06, DYP-ME007, JSN-SR04T & Parallax PING)))™.
* Built-in digital filter method ping_median() for easy error correction
  (use SONAR_ITERATIONS build flag to configure).
* Allows setting of a maximum distance where pings beyond that distance
  are read as no ping or clear (use SONAR_MAX_DISTANCE build flag).

improved CSS to comply with CODACY rules