Removed the 'wu' and 'wd' constants for love.mousepressed, added new love.wheelmoved(x, y) event callback.

+x is mousewheel-right, +y is mousewheel-up.

--HG--
branch : minor

src/modules/mouse/Mouse.h

@@ -44,8 +44,6 @@ public:
 		BUTTON_RIGHT,
 		BUTTON_X1,
 		BUTTON_X2,
-		BUTTON_WHEELUP,
-		BUTTON_WHEELDOWN,
 		BUTTON_MAX_ENUM
 	};