menu button added
Added 'break' after TwoPlayer case, so that we can go back to menu
position of button is set now
Merge branch 'menu-button' of github.com:muhammadyaseen/CheckersGameTurboC into menu-button
Add a fix for the AI bug which will not cause segfaults. Basically I made sire the mouse is on the checkerboard before calling the GetClickedCell function. Other than that, fixed a minor bug of the game continuing in AI mode when you switch to 2Player mode.
Added a line of comment to make codition clear