* MQTT discovery factoring
* add DHT discovery
* BME topic macro change
* add sensors to ha discovery
* correct a comment typo #327
* let the possibility at buildtime to don't publish service data
* reduce string usage
* change MQTT ONOFF actuator to ON OFF commands instead of true false
* add ZactuatorONOFF discovery
* add simple publishing for GPIO input
* Add RF switch and gateway discovery
* factoring of the publishing function
* integration of json publishing to MQTT
* receiving and transcode json messages from mqtt
* replace the TRACE runtime condition by a buildtime one so as to decrease program size
* remove retainFlag parameter not necessary for the moment
* Increase the scope of tests for arduino mega and esp32
* Update arduinojson library to 5.13.3
* add macros to choose between simple or json publishing or both
* differentiate build test for ATmega2560
* correct wrong sprintf definition
* change IDE version for continuous integration
* let default warning level in arduino ide
* correct pins for ESP32
* reorganize user_config
Florian