added seralise (write) functions

Updated copyright messages & repurposed commented out debug code as
seralise (write) functions for game state & moves.
added .gitignore

to hide build product & debug/logging files
Executable can now be used as a simple AI server

Serialises game state in, takes AI name on the command line, outputs
AI's selected move for that game state.

For example:

./a.out AllLow < game.txt