chrss update 16

This update includes a fairly major refactoring of chrss's chess engine. It should make it easier to add new features in the future.

Beyond that the only (noticeable) new feature is that you can now get the Forsyth-Edwards Notation (FEN) for a game. This is a standard format for describing the current state of a game and forms the start of an API for chrss - it would allow one (for example) to write a "widget" for viewing the state of a game.

For example the FEN for game 1 looks like:

r1bk1b2/ppp1q3/2np2Np/4p1nB/8/2N5/PPPP1PPP/R1BQ1RK1 b - - 0 11

You can access the FEN for a game by clicking on the "FEN" link at the bottom of each board.

In terms of an API I should next be tackling Portable Game Notation (PGN), which should also then allow one to import games into other chess programs.