Running Nine Men's Morris.

To run the game, one can either use the Controller.Main class in the main branch, which will display the game through the console, or run the Controller.Main class in the GUI_skeleton branch, which will display it through a UserInterface.GUI. As of now, we decided not to use only the UserInterface.GUI because, unlike the console display, it does not implement the loading and saving part of the game. Note, moreover, that though there is a UserInterface.GUI class in the main branch, it is not the most current one and lacks many features. The most current one has not been merged into the main branch because it required signficant changes in other classes, especially Controller.GamePlay1. Such changes would conflict with the way the console version runs, and this is why GUI_skeleton has not been merged with main.