Rearranged the using-s of the classes so now the System namespaces are at the top
removed the Mine.cs and Flag.cs classes
created an abstract class Cell  that is inherited by 2 other classes
implemented the Visitor pattern and created 4 different visitors to make changes on the RegularCell and MineCell classes
changed some of the logic in the gameBoard so now it works with the cells and returns Cell[,]