Implemented skinnable theme songs.

Plays a theme song when opsu! starts (can be disabled in options).  The default song is "welcome to osu!" by nekodex, uploaded by CyberKitsune.

To change the song, place a new "theme.osu" in the skins folder and edit the file name, metadata, and song length (at minimum).

Signed-off-by: Jeffrey Han <itdelatrisu@gmail.com>

src/itdelatrisu/opsu/states/Splash.java

@@ -18,6 +18,7 @@
 
 package itdelatrisu.opsu.states;
 
+import itdelatrisu.opsu.MusicController;
 import itdelatrisu.opsu.Opsu;
 import itdelatrisu.opsu.OsuParser;
 import itdelatrisu.opsu.OszUnpacker;
@@ -140,6 +141,10 @@ public class Splash extends BasicGameState {
 			Opsu.groups.init();
 			((SongMenu) game.getState(Opsu.STATE_SONGMENU)).setFocus(Opsu.groups.getRandomNode(), -1, true);
 
+			// play the theme song
+			if (Options.isThemSongEnabled())
+				MusicController.playThemeSong();
+
 			game.enterState(Opsu.STATE_MAINMENU);
 		}
 	}