Cleaned up code, Added Game.Exit, Fixed Menu

Menu: "Play" is now red on startup
Fixed game not exiting when StateStack is empty
Added Game.Exit()
Updated some code to use Game.Exit
Removed unused Game.PlayerSpeed
Removed unused Game.mPlayerSprite
Removed unused Game.mTexture
Removed unusued Game.mIsMovingUp, mIsMovingDown, mIsMovingLeft,
mIsMovingRight
Updated MenuState.HandleEvent
Updated gitignore