Class playn.core.Mouse

Added Methods
ButtonEvent buttonEvents(Event)	Checks whether {@code event} is a {@code ButtonEvent} and returns it (casted appropriately) if so.
MotionEvent motionEvents(Event)	Checks whether {@code event} is a {@code MotionEvent} and returns it (casted appropriately) if so.
WheelEvent wheelEvents(Event)	Checks whether {@code event} is a {@code WheelEvent} and returns it (casted appropriately) if so.