Implemented the isMoveLegal method for
each piece, except for the pawn since it
is more complicated and thus we
need more functionality to determine
whether a move is legal or not.
Merge branch 'master' of github.com:marsj725/TDDD49 into legalMoves

Conflicts:
	Engine/Pawn.cs
Merge pull request #11 from samni698/legalMoves

Implemented the isMoveLegal method