start of the development of the ludogene plugin
Merge branch 'master' into ludogene
basic game storing mechanics and game integration in place
it's possible to play a 2 players tribo game (ugly rendering, no score displayed)
slightly less ugly graphics for Tribo games
fixing tribo rules implementation
display of scores and current player in Tribo games
Tribo is now playable
Tribo : potential and realized lines are shown on the board
fixed a few bugs in Tribo rendering
Tribo : mobile layout, server side caching of games, notifications.

Games are now cached server side instead of being loaded from DB and computed each time a move is done.
Layout of the game is different for thin screens.
Moves are seen as new messages for observers and as pings for the other player (the tab title and icon change, and a desktop notification may appear)