Multiplayer : Cooperative mode

Implementing Multi-player was an easy task. I only changed the "Player* player" to a "vector players".
Actually the game is in cooperative mode. But it can be easily changed to another multi-player mode. The money is individual but the rewards are shared whoever killed the unit.

The number of players in-game is not limited, which is a good news for my mmorpg version (will come in a long long time I guess)

Technically I moved the player variable into the controller. Like this, once the network will be implemented, each client will have his own controller and the model will not care who is hosting the game (specially if I host it on a dedicated server). To test it I just simulated many players and I use F7 key to switch.

To help the player to see the tower owner I decided to put a flag on it with the color of the player (red, blue, green ...). I think it is a cool way to do that.

This is all for now.

Multi-player mode