Remove need for client to register for updates.

[JoshuaJB]

We should remove need for a client to register for updates and just use presence stanzas. (Fixing this should also fix #5 )

[JoshuaJB]

This is mostly done, I think we now just send registration as an extra assurance.

[JoshuaJB]

Alright, I reviewed the code and it looks like everything besides the leaderboard should automatically detect players and doesn't require registration.