fixes Square.fromAlgebraic - wrong variable was used to index object
corrects reference to _activeColour.fenString in Position
corrects references to Board.getSquaresBetween and Square module in Board
corrects reference to _targetPiece for null check in Move
adds playerIsInCheck to Position - forwards call to _board
corrects references to Board's internal board and to pieceType in getReachableSquares
corrects reference to colour.opposite in Game and adds Result require
cleans up Result and gives it a simple public interface
replaces first test with basic one move test in Game tests