connection.disconnect() added.

It fires:

connection.ondisconnected = function(event){
----  if( event.isSocketsDisconnected == true ) { }
};

connection.disconnect() means, "Disconnect all SOCKETS, all PEERS, all
STREAMS (if keepStreamsOpened isn't used) and everything except
RTCMultiConnection object).

You can use it like this:

connection.close();
connection.disconnect();

This method is useful in "session-reinitiation" scenarios.

When connection is disconnected, you need to call "connection.connect"
or "connection.join" to join the session.