Feature - different zones / worlds / levels

[kumavis]

If we're going to have a universe with persisting public spaces, private challenge rooms, user created content, and more, we're going to need to be able to navigate between 'rooms'/'realms'/'worlds'.

I imagine the challenge worlds will mostly be single player entities. But if you got stuck it would be nice to be able to invite someone along to help you.
Perhaps when you go to try a challenge room, you first fork it into your collection. Then you can start serving it
yourself.