Made the faction seat parameter in level files used to know whether a player or an AI is to be added.

As a result, the default level has got two AIs to play against (red and blue.)
First pass at cleaning up the Game Map class.

- Code style guidelines.
- Copyright headers.

I had to drop the next level parameter since it was broken and changing level
shouldn"t work like that.
I also simplified a bit the code creating and refreshing tiles as a side-effect.
Code guidelines to Player.cpp/files

And few simplifications.
Code guidelines on ProximityTrap, RadialVector2 and Random source files.
MEDIA: Adapted the level files to latest changes.