* add option to strip webUI for ESP8266 (reduce code size, add ESP32 special features; `IF_ESP32` directives)
* started to get CMT info into `system` - not finished
Display class gets access to App interface and HmRadio
Display class prepares relevant online information for displays in new DisplayData structure
Displays get pointer to DisplayData and only use information received from there
* fixed docu #1085
* changed active power limit MqTT messages to QOS2 #1072
* improved alarm messages, added alarm-id to log #1089
* trigger power limit read on next day (if inverter was offline meanwhile)
* disabled improv implementation to check if it is related to 'Schwuppdizitaet'
* changed live view to gray once inverter isn't available
* added inverter status to API
* changed sum of totals on WebGui depending on inverter status #1084
* merge maximum power (AC and DC) from PR #1080
* MqTT alarm data was never sent, fixed
* REST API: added alarm data
* REST API: made get record obsolete
* REST API: added power limit acknowledge `/api/inverter/id/[0-x]` #1072
* 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
* merge PR #1056, visualization html
* update MqTT library to 1.4.4
* update RF24 library to 1.4.7
* update ArduinoJson library to 6.21.3
* set minimum invervall for `/live` to 5 seconds
Warning: old exports are not compatible any more!
further save settings improvements (only store inverters which are existing)
improved display of settings save return value
made save settings asynchronous (more heap memory is free)
fix add inverter `setup.html` #766
fix MQTT retained flag for total values #726
renamed buttons for import and export `setup.html`
added serial message `settings saved`
added part of mac address to MQTT client ID to seperate multiple ESPs in same network
added dictionary for MQTT to reduce heap-fragmentation
removed `last Alarm` from Live view, because it showed always the same alarm - will change in future
fix blue LED lights up all the time #672
fix installing schedulers if NTP server isn't available
improved zero values on triggers #671
hardcoded MQTT subtopics, because wildcard `#` leads to errors
rephrased some messages on webif, thx to @Argafal#638
reenabled FlashStringHelper because of lacking RAM
complete rewrite of monochrome display class, thx to @dAjaY85 -> displays are now configurable in setup