Fix canvasBoundingBox -> add parameters
events in socket.js for everybody stocking data

Everybody can now stock data in "users", an object who need to be filled
using:
"create player" (emit client side), create player will assign the
localName if nobody is connected with the same localName. If someone is
already connected, it will instead use socket.sessionid.
"modification player", this event update server-side all the data
transmitted by the connector. object is
{player:{ALL-PROPERTIES},id:My-ID};
"load players" send client-side, all the data of the users object.