Create game flow

[Keboo]

We want two players (sharing a single screen, and input devices) to be able to take turns playing the game. We expect that players will simply take turns using the mouse when it is their turn.

When a player clicks on an unopened space.
If it contains a mine, display a flag, the player gains a point.
If it contains a number greater than 0 open the space and reveal the value.
If it contains a 0 open all adjacent spaces and recurse the opening logic.

When a player does not click on a mine, the current player's turn is over and it is the next player's turn.