Removed old AI code ready for the re-write of the AI engine and datastructure handling.

 On branch ai_restructure
	modified:   ai.c
	modified:   ai.h
	modified:   main.c
Changed the build system to used cmake
 On branch ai_restructure
	modified:   .gitignore
	new file:   CMakeLists.txt
	new file:   src/CMakeLists.txt
	renamed:    ai.c -> src/ai.c
	renamed:    ai.h -> src/ai.h
	renamed:    bitboard.c -> src/bitboard.c
	renamed:    bitboard.h -> src/bitboard.h
	renamed:    constants.h -> src/constants.h
	renamed:    main.c -> src/main.c
	renamed:    player.c -> src/player.c
	renamed:    player.h -> src/player.h