Follow-up to #64.

- Removed NEW_SLIDER option, and use the skin "SliderStyle" instead.  Uses the new style by default, unless STYLE_PEPPYSLIDER is specified.
- Check if OpenGL 3.0 is supported before trying to draw new style sliders.
- Fixed compilation warnings; removed unneeded fields and imports.
- Filled in some missing Javadocs.
- Style changes.

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

src/itdelatrisu/opsu/states/Game.java

@@ -31,8 +31,8 @@ import itdelatrisu.opsu.audio.MusicController;
 import itdelatrisu.opsu.audio.SoundController;
 import itdelatrisu.opsu.audio.SoundEffect;
 import itdelatrisu.opsu.beatmap.Beatmap;
-import itdelatrisu.opsu.beatmap.HitObject;
 import itdelatrisu.opsu.beatmap.BeatmapParser;
+import itdelatrisu.opsu.beatmap.HitObject;
 import itdelatrisu.opsu.beatmap.TimingPoint;
 import itdelatrisu.opsu.db.BeatmapDB;
 import itdelatrisu.opsu.db.ScoreDB;
@@ -1025,7 +1025,7 @@ public class Game extends BasicGameState {
 		if (beatmap == null || beatmap.objects == null)
 			throw new RuntimeException("Running game with no beatmap loaded.");
 
-		//free all previously cached hitobject to framebuffer mappings if some still exist
+		// free all previously cached hitobject to framebuffer mappings if some still exist
 		FrameBufferCache.getInstance().freeMap();
 
 		// grab the mouse (not working for touchscreen)
@@ -1393,7 +1393,7 @@ public class Game extends BasicGameState {
 		Circle.init(container, circleSize);
 		Slider.init(container, circleSize, beatmap);
 		Spinner.init(container);
-		Curve.init(container.getWidth(),container.getHeight(),circleSize);
+		Curve.init(container.getWidth(), container.getHeight(), circleSize);
 
 		// approachRate (hit object approach time)
 		if (approachRate < 5)

src/itdelatrisu/opsu/states/OptionsMenu.java

@@ -59,8 +59,7 @@ public class OptionsMenu extends BasicGameState {
 			GameOption.SCREENSHOT_FORMAT,
 			GameOption.NEW_CURSOR,
 			GameOption.DYNAMIC_BACKGROUND,
-			GameOption.LOAD_VERBOSE,
-			GameOption.NEW_SLIDER
+			GameOption.LOAD_VERBOSE
 		}),
 		MUSIC ("Music", new GameOption[] {
 			GameOption.MASTER_VOLUME,