Removed some unneeded methods.

- Removed "isImplemented" field from GameMod as all of the base mods have been implemented.
- Removed Utils.getBoundedValue() methods in preference for Utils.clamp().

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

src/itdelatrisu/opsu/ui/MenuButton.java

@@ -460,7 +460,7 @@ public class MenuButton {
 			return;
 
 		int d = delta * (autoAnimationForward ? 1 : -1);
-		if (Utils.getBoundedValue(time, d, 0, animationDuration) == time) {
+		if (Utils.clamp(time + d, 0, animationDuration) == time) {
 			if (reverseAtEnd)
 				autoAnimationForward = !autoAnimationForward;
 			else {