Support authorisation

[aidanlister]

We need to provide an authentication backend so that users logging in via facebook, or the normal auth backend, can be treated identically.

We need to come up with a strategy for the following scenarios:
a) User registers / logs in with facebook. Their authenticate() session should be no longer than their graph access token.
b) Must support de-authorise callback
c) User has registered already and wants to associate their facebook account.

[aidanlister]

I've pushed some rudimentary code to handle this, but we need to have a realtime discussion about how we're going to handle this elegantly.

[jgorset]

Yes. How about we open a #pythonforfacebook channel on an IRC server?

[aidanlister]

irc.freenode.net #pythonforfacebook :)