Mqtt discovery for ha (#323)

* 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

ZgatewayRFM69.ino

@@ -231,9 +231,7 @@ boolean RFM69toMQTT(void) {
 #ifdef jsonPublishing
   void MQTTtoRFM69(char * topicOri, JsonObject& RFM69data) {
   
-    String topic = topicOri;
-  
-    if (topic == subjectMQTTtoRFM69) {
+   if (strcmp(topicOri,subjectMQTTtoRFM69) == 0){
       const char * data = RFM69data["data"];
       trc(F("MQTTtoRFM69 json data analysis"));
       if(data){