Added SDL_GameControllerUpdate().

include/SDL_gamecontroller.h

@@ -160,6 +160,15 @@ extern DECLSPEC SDL_Joystick *SDLCALL SDL_GameControllerGetJoystick(SDL_GameCont
  */
 extern DECLSPEC int SDLCALL SDL_GameControllerEventState(int state);
 
+/**
+ *  Update the current state of the open game controllers.
+ *  
+ *  This is called automatically by the event loop if any game controller
+ *  events are enabled.
+ */
+extern DECLSPEC void SDLCALL SDL_GameControllerUpdate(void);
+
+
 /**
  *  The list of axii available from a controller
  */