Added a side member to the Piece class.
Validates and generate black side moves in addition to white side moves. Tests are not yet updated.
Fixed all tests except those which fail due to the need to take turns which has not been implemented yet.
Fixed all test cases with both black and white pieces and alternating moves. Fixed a bug that was not properly filtering a piece's last location from its own occupied paths after a move.
Updated board printer for black side. Added a TODO to fix an issue where the queenside castle is being generated for black when it is not allowed.
Merge branch 'master' of https://github.com/daveswartz/mateinone

Conflicts:
	README.md
Updated readme.