For each event add a client identification.

[cdupetit]

When you use the $un function, it removes all the handlers registered on an event.
But if you want to remove just a particular handler on an event, you can't.
With this evolution when you register a handler, you can specify the associate client.
Example:
ws.$on({event: "$close", client: "client1"}, function() {} );
ws.$on({event: "$close", client: "client2"}, function() {} );
And when you want to unregister this handler, you can do the same.
ws.$un({event: "$close", client: "client1"});
The handler of "client2" is still working.

[LeleDev]

+1 for the feature (didn't test the code)