Replaced native cursors with skinnable ones.

- Added support for both the new (2013+) and old cursor styles.  These can be toggled on/off in the configuration file.
- Added cursor images by XinCrin (old style) and teinecthel (new style).

Other changes:
- Refactoring: Created a "Utils" module, containing methods and constants that didn't belong in the "Options" state and some duplicated drawing methods.
- Mouse is now grabbed during gameplay.
- Removed 'optionsChanged' switch, simplifying adding new options.

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

src/itdelatrisu/opsu/objects/Spinner.java

@@ -22,6 +22,7 @@ import itdelatrisu.opsu.GameScore;
 import itdelatrisu.opsu.MusicController;
 import itdelatrisu.opsu.OsuHitObject;
 import itdelatrisu.opsu.SoundController;
+import itdelatrisu.opsu.Utils;
 import itdelatrisu.opsu.states.Game;
 import itdelatrisu.opsu.states.Options;
 
@@ -127,7 +128,7 @@ public class Spinner {
 		//spinnerOsuImage.drawCentered(width / 2, height / 4);
 
 		// darken screen
-		g.setColor(Options.COLOR_BLACK_ALPHA);
+		g.setColor(Utils.COLOR_BLACK_ALPHA);
 		g.fillRect(0, 0, width, height);
 
 		if (timeDiff > 0)