Implementing network gaming

-- Preparation works :
The first step whould be to use one board instead of three (at least of three) to remove the complexity.
   So instead of each emplacement being described as the board and the x and y we would have directly one global coordinate systeme. During migration x and y represent the old coordinate system (accompanied by information of which board they belong to) and gy, gy would represent a position in the global coordinate system. g_func() are function using globale coordinate in the Game class and _func in the UI class (the migration will be faster here so they will soon regain the old name)
  This work is done in the branch lp:~pyhalebarde/pyhalebarde/onebranch
  [in progress]

The second one would be to pass unit "action" from Game class to movement instead of just making unit appear and disappear. This would avoid UI having to know about the board class and avoid hacks to make things work. The interface would actually understand better the global action so we could eventually make animations. This would also make easier the creation of history and undo-redo action.

Then we need to do the actual work .. [to complete]