Federations
Federations are a collection of players, i.e. a club or group of friedns.
Every player can found one or more federations. The founder of a federation becomes its administrator by default. Federations can have mulitple admins. The last remaining admin can not leave the admin role.
Federations can be 'invite only' or 'open for all'. If invite only, admins can invite players in the admin interface.When founding a new game, federation admins can configure the game so that only members of the federation can join the game.