Add support for custom instruments in datapack export

This also stops a crash where the datapack exporter will not be able to export a song if it used custom instruments in the past.
The custom instrument's playsound IDs are the name of the custom instrument. This allows regular minecraft sounds to be used as instruments.

Author: ShinkoNet

scripts/dat_generate/dat_generate.gml

@@ -12,7 +12,7 @@ for (a = 0; a <= o.enda; a ++) {
 	    for (b = 0; b <= o.collast[a]; b += 1) {
 	        if (o.song_exists[a, b] && (o.lockedlayer[b] = 0 || o.dat_includelocked)) {
 	            if (o.song_key[a, b] > 32 && o.song_key[a, b] < 58) {
-	                instrument = dat_instrument(ds_list_find_index(other.instrument_list, o.song_ins[a, b]))			
+	                instrument = dat_instrument(ds_list_find_index(other.instrument_list, o.song_ins[a, b]))
 	                pitch = dat_pitch(o.song_key[a, b])
 					blockvolume = o.layervol[b]/100
 					s = o.layerstereo[b] // Stereo values to X coordinates

scripts/dat_instrument/dat_instrument.gml

@@ -1,40 +1,46 @@
 //dat_instrument()
 //returns right minecraft id
 
-var instrument = argument0
+var instrumentnumber = argument0
 var str = "minecraft:block.note_block."
-
-switch (instrument) {
-    case 0:
-        return str + "harp"
-    case 1:
-        return str + "bass"
-	case 2:
-		 return str + "basedrum"
-	case 3:
-		 return str + "snare"
-	case 4:
-		return str + "hat"
-	case 5:
-		return str + "guitar"
-	case 6:
-		return str + "flute"
-	case 7:
-		return str + "bell"
-	case 8:
-		return str + "chime"
-	case 9:
-		return str + "xylophone"	
-	case 10:
-		return str + "iron_xylophone"	
-	case 11:
-		return str + "cow_bell"	
-	case 12:
-		return str + "didgeridoo"	
-	case 13:
-		return str + "bit"	
-	case 14:
-		return str + "banjo"	
-	case 15:
-		return str + "pling"	
+var ins
+if instrumentnumber < 16 {
+	switch (instrumentnumber) {
+	    case 0:
+	        return str + "harp"
+	    case 1:
+	        return str + "bass"
+		case 2:
+			 return str + "basedrum"
+		case 3:
+			 return str + "snare"
+		case 4:
+			return str + "hat"
+		case 5:
+			return str + "guitar"
+		case 6:
+			return str + "flute"
+		case 7:
+			return str + "bell"
+		case 8:
+			return str + "chime"
+		case 9:
+			return str + "xylophone"	
+		case 10:
+			return str + "iron_xylophone"	
+		case 11:
+			return str + "cow_bell"	
+		case 12:
+			return str + "didgeridoo"	
+		case 13:
+			return str + "bit"	
+		case 14:
+			return str + "banjo"	
+		case 15:
+			return str + "pling"
+	}
+}
+if instrumentnumber >= 16 {
+	ins = ds_list_find_value(other.instrument_list,instrumentnumber)
+	return string("minecraft:"+ins.name)
 }