Added initial Melody Playback Ability

Now, controlled via MQTT a Playback of a melody can Start, Stop, Pause 
etc. 

Settings like speed, total duration, pauses etc can be set.

config.h

@@ -2,9 +2,14 @@ const char* ssid     = "SmartNet";
 const char* password = "smartpass";
 const char* hostname = "ESP32_mqtt_test";
 
+const IPAddress MQTT_HOST(10,98,20,10);
+const int MQTT_PORT = 1883;
+
+#define MQTT_USER "esp32_vesper"
+#define MQTT_PASS "vesper"
+
 IPAddress ip(10, 98, 30, 150);
 IPAddress gateway(10, 98, 30, 1);
 IPAddress subnet(255, 255, 255, 0);
 
-#define MQTT_USER "esp32_vesper"
-#define MQTT_PASS "vesper"
+#define DEV_ID "id-96638646"