Create .square package to organise square types.

Neutral Square (possibly incl. access), NonPlayableSquare and RoomSquare
all extend Square and hold their position and other info.
BoardFrame now creates 2D of squares based on Board.map int array.
BoardFrame now includes basic layouts, including some buttons.
Made Board.maps[][] private (as per .getMap()).
Having issues with scalability of window, will come back to it.