- "MUC user joined", "MUC user left" and class XMPPHandler are managed directly in RoomGame
- renamed __init__ parameters 'player_init_data' to 'player_init' and 'options' to 'game_init'
- pass the players list in radiocol method 'createGame' and signal 'radiocolStarted' (needed for invitation system and for UI players identification)
- added some parameters to manage who can invite, who can join, who to wait for... managed with check***Auth methods
- joining a game that is already launched may be possible, regarding these parameters and the invitation list
- leave and join a game again is partly managed: new tarot round is launched, we should keep playing the same round instead
- method to get the MUC service moved to plugin_xep_0045
- joinMUC returns the muc name (given by user or generated)
- getUniqueName can receive a specified service in argument
