Possible classes:
	GUI
		Display the game board
		Show the selected first half of the move
		Show the list of moves that are performed so far
		Show the captured pieces
		Show highlighting for the most recent move
		Symbol for display?
	GameState
		Direct storage of piece data in a 2D array (speed of computation)
		Know whose turn it is
		Be able to set up the starting positions
		Be able to perform the move (remove piece if a capture, promote to queen if get to the end)
	Square
		What pieces (if any) occupies it
		Knowledge of whether or not castling, en passant are available
	Move
		Represents a source and destination square
		Knows whether or not it was a capture, check, etc.

Where are the rules going to be programmed in?
	A piece has to be aware of other stuff going on around it in order to calculate if a move is legal or not.

What is a piece location useful for?
	Checking for legality of moves
	Drawing the pieces on the board

Duplicating game states will be easier if we don't have lots of objects attached to the game board.