Metrics logging now includes average time taken per frame. Also, metrics now come in a single JSON payload to /metrics.

include/my_mqtt.h

@@ -18,6 +18,7 @@ void mqtt_setup();
 void mqtt_loop();
 
 void mqtt_publish(const char* topic, int number);
+void mqtt_publish(const char* topic, const char* message);
 
 void mqtt_log(const char* message);
 void mqtt_log(int number);