Continuation of 53c79c5 - HitObject name changes.

Attempts to eliminate any confusion between OsuHitObject (raw, parsed hit objects) and HitObject (interface for game object types).
- Renamed "HitObject" interface to "GameObject", since these objects are specific to gameplay.
- Renamed "OsuHitObject" to "HitObject", since these objects are primarily containers for parsed data.

Sorry if the name-swapping is confusing; these should be better names in the long run.

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

src/itdelatrisu/opsu/beatmap/Beatmap.java

@@ -188,7 +188,7 @@ public class Beatmap implements Comparable<Beatmap> {
 	 */
 
 	/** All hit objects. */
-	public OsuHitObject[] objects;
+	public HitObject[] objects;
 
 	/** Number of individual objects. */
 	public int