TODO

   1 Impossible to play / triple move in Doublemove : turn issues, maybe because a move is sent twice to the server...
   2 => solution = sign (hash?) moves, and if an already received signature received again, ignore?
   3
   4 add variants : Chakart first (dark,cylinder)
   5 Dark Racing Kings ?
   6 Checkered-Teleport ?
   7
   8 Otage, Emergo, Pacosako : fonction "buildPiece(arg1, arg2)" returns HTML element with 2 SVG or SVG + number
   9 réfléchir aux animations par variante (reversi, Chakart, Atomic, ...)