Major track length-related updates.

- Parse and store the end time for every beatmap (i.e. end time of last hit object).
- Added a 'length' sorting tab.
- Added 'length' search condition.
- Removed 'getTrackLength()' and 'getTrackLengthString()' methods, as they are no longer needed.
- Added a loader spritesheet animation to render during MP3 conversions (in place of track length rendering upon completion).

Other changes:
- Added a yellow progress circle during lead-in time.
- Fixed sorting tab positioning.
- Slightly increased button animation speed in "Main Menu Exit" state.

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

src/itdelatrisu/opsu/states/MainMenu.java

@@ -190,7 +190,7 @@ public class MainMenu extends BasicGameState {
 		g.setColor(Color.white);
 		if (!MusicController.isTrackLoading())
 			g.fillRoundRect(width - 168, 54,
-				148f * MusicController.getPosition() / MusicController.getTrackLength(), 5, 4);
+				148f * MusicController.getPosition() / osu.endTime, 5, 4);
 
 		// draw text
 		g.setFont(Utils.FONT_MEDIUM);