General:
Fixed a bug with the Knight's move validation.

ChessHelp.java:
Fixed pathing bug: negative incrementer reassignment, not positive, because we're playing upside down.

BoardLocation.java:
Changed the toString() to be effective equivalent of java.awt.Point

Queen.java:
ArithmeticException (x/0) prevention by checking Rook-type moves validity first

Knight.java:
Changed how he sees the square he's moving to. Null check really