Implemented all csf handling

audio/SongInstance.java

@@ -8,22 +8,32 @@ public class SongInstance {
 	private String difficulty;
 	
 	private List<ObjectInstance> objects;
+	private List<ButtonInstance> buttons;
 	
 	public SongInstance(String difficulty)
 	{
 		this.difficulty = difficulty;
 		
 		objects = new ArrayList<ObjectInstance>();
+		buttons = new ArrayList<ButtonInstance>();
 	}
 	
 	public void addObjectInstance(ObjectInstance obj)
 	{
 		objects.add(obj);
 	}
+	public void addButtonInstance(ButtonInstance btn)
+	{
+		buttons.add(btn);
+	}
 
 	public List<ObjectInstance> getObjects() {
 		return objects;
 	}
+	
+	public List<ButtonInstance> getButtons() {
+		return buttons;
+	}
 
 	public String getDifficulty() {
 		return difficulty;