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.

build/sketch/bellEngine.hpp

@@ -0,0 +1,78 @@
+#line 1 "C:\\Users\\espi_\\Documents\\Arduino\\vesper\\bellEngine.hpp"
+// MELODY PLAYBACK WILL BE HANDLED HERE
+#include <vector>
+
+extern volatile bool playing;
+extern melody_attributes melody;
+extern uint16_t relayMask;
+extern bool forceStop;
+
+void loop_playback(std::vector<uint16_t> &melody_steps);
+void itsHammerTime(uint16_t note);
+
+
+void bellEngine(void *parameter) {
+
+	// SETUP TASK 
+	 
+	for (;;) {
+		
+		// Playback until stopped (Completes AT LEAST 1 full loop)
+		loop_playback(melody_steps);
+
+ /* 	
+		UBaseType_t highWaterMark = uxTaskGetStackHighWaterMark(NULL);
+		Serial.print("Stack high water mark: ");
+		Serial.println(highWaterMark);
+ */
+	}
+
+}
+
+
+
+
+void loop_playback(std::vector<uint16_t> &melody_steps) {
+
+	
+
+	while(playing){
+	
+		// iterate through the beats and call the bell mechanism on each beat
+		for (uint16_t note : melody_steps) { 
+			if (forceStop) return;
+			itsHammerTime(note);
+      int tempo = melody.speed;
+			vTaskDelay(pdMS_TO_TICKS(tempo));
+		}
+		
+		// pause for "interval_duration" 
+		vTaskDelay(pdMS_TO_TICKS(melody.interval_duration));
+		
+		// pause for standard "breath-out" duration if interval was less than 3000ms
+		if (melody.interval_duration<3000) vTaskDelay(pdMS_TO_TICKS(3000));
+		
+	}
+
+}
+
+
+void itsHammerTime(uint16_t note){
+	
+	// THIS NEEDS REWORK, TO WAIT, DYNAMICLY PER RELAY
+	// MUST BE CONFIGURABLE REMOTELY
+	
+	for (uint8_t i=0; i<16; i++) {
+			if (note & (1 << i)) {
+				relays.digitalWrite(i, LOW);
+			}
+		}
+		
+	vTaskDelay(pdMS_TO_TICKS(relayDurations[0]));
+	
+	for (uint8_t i=0; i<16; i++) {
+		relays.digitalWrite(i, HIGH);	
+	}
+	
+	
+}