More graphical updates, some code cleanup, and minor fixes.

- The MenuButton class now fully supports hover effects (scale, fade, rotate) for Animations.
- Used a fixed location for the selection buttons in the song menu (previously based on the "back" button width, which varies widely in different skins).
- Added hover effects for "retry" and "exit" buttons in the ranking screen.
- Changed animation speed of back/skip buttons.
- Fixed a bug where main menu showed the incorrect number of songs loaded during searches.
- Removed unneeded draw() methods in Utils for color filters (since 69f5aa5).
- Moved Utils.drawCentered(Image, ...) into the Image class.
- Added overwritten Image class to Maven excludes.

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

src/itdelatrisu/opsu/states/GameRanking.java

@@ -84,6 +84,8 @@ public class GameRanking extends BasicGameState {
 				width - (exit.getWidth() / 2f),
 				(height * 0.97f) - (exit.getHeight() / 2f)
 		);
+		retryButton.setHoverFade(0.6f);
+		exitButton.setHoverFade(0.6f);
 	}
 
 	@Override
@@ -119,6 +121,10 @@ public class GameRanking extends BasicGameState {
 		Utils.updateCursor(delta);
 		Utils.updateVolumeDisplay(delta);
 		int mouseX = input.getMouseX(), mouseY = input.getMouseY();
+		if (data.isGameplay()) {
+			retryButton.hoverUpdate(delta, mouseX, mouseY);
+			exitButton.hoverUpdate(delta, mouseX, mouseY);
+		}
 		Utils.getBackButton().hoverUpdate(delta, mouseX, mouseY);
 	}
 
@@ -174,8 +180,11 @@ public class GameRanking extends BasicGameState {
 		if (!data.isGameplay()) {
 			if (!MusicController.isTrackDimmed())
 				MusicController.toggleTrackDimmed(0.5f);
-		} else
+		} else {
 			SoundController.playSound(SoundEffect.APPLAUSE);
+			retryButton.resetHover();
+			exitButton.resetHover();
+		}
 	}
 
 	@Override