Center messages about win and tie. Refactor view.c.
Change * to [] in argument list of printTitle() function
Shorten singleplayer() function
Add checkForEndOfGame() function.
Do not check second if statement at every run of function
Shorten name of the argument variable
Add normal difficulty level AI
Get rid of unnecessary recursion on easy level
Add new files: ai.c, ai.h, game_modes.c and game_modes.h. Update Makefile.