Added default values for Frame and Position properties to Entity and Sprite; Added Load overload to Sprite; Changed Load method of Entity to call overloaded Load method of Sprite
Added gamePadState, keyboardState, prevGamePadState and prevKeyboardState properties to Game, changed detectInput method signature, added detectInputOnce method, refactored processInput method
Added paused property to Game, added pause check in Update and processInput methods, updated toggleMenu method