Abstracting the graphic representation part

modified:   HDCEngine.hs
	new: printASCII

modified:   SnakeGame.hs
	deleted: gameStateStr
	deleted: gameStateLine
	deleted: snakeNfood2Str
	modified: foodList
	modified: snakeList
	new: gameStateFormat
	new: mergeGameStateList
	new: compareASCIICell