* merge PR #1069 make MqTT client ID configurable
* fix#1016, general MqTT status depending on inverter state machine
* changed icon for fully available inverter to a filled check mark #1070
* fixed `last_success` update with MqTT #1068
* removed `improv` esp-web-installer script, because it is not fully functional at this time
* next attempt to fix yield day for multiple inverters #1016
* fix export settings date #1040
* fix time on WebUI (timezone was not observed) #913#1016
* fix HMS-800 and HMS-1000 assignments #981
* make nrf enabled all the time for ESP8266
* fix menu item `active` highlight for 'API' and 'Doku'
* fix MqTT totals issue #927, #980
* reduce maximum number of inverters to 4 for ESP8266, increase to 16 for ESP32
reduced maximum allowed JSON size for API to 6000Bytes #660
small fix: output command at `prepareDevInformCmd` #692
improved inverter handling for MQTT #671
added icons to index.html, added wifi-strength symbol on each page
moved packet stats and sun to system.html
refactored communication offset (adjustable in minutes now)