Namespace in room functions

[skortchmark9]

Hey Miguel - I was really stoked to see that you added the sid param to the rooms() method. Now I can address clients in my HTTP API! The only thing currently missing is the option to pass in a namespace: currently I have to do:

request.namespace = '/'
rooms(sid=client_sid)

With that change, you could remove the

This is a function that can only be called from a SocketIO event handler.

restriction!