Further improve Hass integration

[emontnemery]

A major remaining Home Assistant annoyance is error prints when turning off a light because dimmer and RGB keys are missing from the JSON dict:

{"POWER":"OFF"}

A PR on Home Assistant to remove the error prints was rejected: home-assistant/core#18723

This PR instead changes Tasmota to send tele/STATUS message when:

• power is switched
• light property is changed
• state command is received

And also changes Hass configuration to pick light and power status from the tele/STAT JSON dict:

{
  "Time":"2018-12-02T16:51:43",
  "Uptime":"0T00:10:45",
  "Vcc":3.215,
  "SleepMode":"Dynamic",
  "Sleep":0,
  "LoadAvg":999,
  "POWER":"ON",
  "Dimmer":23,
  "Color":"58,0,0,0,0",
  "HSBColor":"0,100,23",
  "Channel":[23, 0, 0, 0, 0],
  "CT":499,
  "Scheme":0,
  "Fade":"OFF",
  "Speed":1,
  "LedTable":"OFF",
  "Wifi":{
    "AP":1,
    "SSId":"SomeWLAN",
    "BSSId":"78:8A:20:D1:0B:21",
    "Channel":11,
    "RSSI":66
  }
}