Add the 0x88 board representation

[Joseph Cassman]

In addition to the simple 8x8 array used to represent the surface of the board add a model that uses a 128 bye array that makes use of the 0x88 coordinate calculation trick for performance.

[Joseph Cassman (joichiro-deactivatedaccount)]

Up to revision 22 tried out a few ideas on how to keep from duplicating too much code. Revision 22 has a structure that seems to work with minimal difficulty and lesser complexity than some other ideas. Probably a better way to divide things up in the end. Parsing SAN and FEN strings brings in the most complexity right now for the library. Need to get a specification back onto the code as all NUnit-style testing has been removed to simplify the problem space. That might be added back in later. First get 0x88 move generation working and then see how the code quality can be improved and verified.

[Joseph Cassman (joichiro-deactivatedaccount)]

Decided to skip implementation of 0x88 and instead implement a more efficient board for the time being. Refactoring for multiple board surface model implementations has been done.