Add sysex messages that make the button LEDs work

(Suggested by @cokeramirez)

Author: rrrapha

res/controllers/Numark-Party-Mix-MKII.scripts.js

@@ -51,8 +51,13 @@ NumarkPartyMix.init = function(_id, _debugging) {
     NumarkPartyMix.browse = new NumarkPartyMix.Browse();
     NumarkPartyMix.gains = new NumarkPartyMix.Gains();
 
-    // 0x00 0x01 0x3F is Numark mfg. ID used in SysEx messages.
-    midi.sendSysexMsg([0xF0, 0x00, 0x01, 0x3F, 0x38, 0x48, 0xF7]);
+    midi.sendSysexMsg([0xF0, 0x00, 0x20, 0x7F, 0x03, 0xF7], 6);
+    midi.sendSysexMsg([0xF0, 0x00, 0x20, 0x7F, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0xF7], 12);
+    midi.sendSysexMsg([0xF0, 0x00, 0x20, 0x7F, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0xF7], 12);
+
+    NumarkPartyMix.heartbeatTimer = engine.beginTimer(250, function() {
+        midi.sendSysexMsg([0xF0, 0x00, 0x20, 0x7F, 0x05, 0xF7], 6);
+    });
 };
 
 NumarkPartyMix.shutdown = function() {