-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)
-Systematically show init+dest squares in PGN, maybe after short notation
-(2 moves list, second for de-ambiguification)
-Button to show all pieces that can move (next to expert mode; change icons)
+PROBABLY WON'T FIX:
+Embedded rules language not updated when language is set (in Analyse, Game and Problems)
+If new live game starts in background, "new game" notify OK but not first move.