Returns the current state of the given hat.
This is represented as an OR'd combination of one or more of the
following constants:
SDL.HAT_CENTERED
SDL.HAT_UP
SDL.HAT_RIGHT
SDL.HAT_DOWN
SDL.HAT_LEFT
SDL.HAT_RIGHTUP
SDL.HAT_RIGHTDOWN
SDL.HAT_LEFTUP
SDL.HAT_LEFTDOWN
The current state of the given hat.