-Styles must be improved (full width for smartphones, ...)
-PGN text is not selectable (understand why?!)
-Change cursor when computer "think" (sablier)
-Tooltip text should fade (even when mouse stay on it, especially for small screens)
-Checkered stage 2: switch button at reserve position (or on top).
-Mode expert: game.js, button on top (with online indicator)
-Turn indicator on top too (black or white)
+For animation, moves should contains "moving" and "fading" maybe...
+(But it's really just for Magnetic chess)
+setInterval "CRON" task in sockets.js to check connected clients
+(every 1hour maybe, or more)