User Registration

[krotscheck]

A new user should be able to register for Owner Credentials- based login/password flow.

[krotscheck]

At this time there doesn't appear to be a canonical "OAuth2" way of permitting dynamic owner registration. As OAuth2 is primarily concerned with Authz vs. Authn, this makes sense, but it leaves us in a bit of a lurch, as users don't actually care that much about the distinction. They just want to log in.

So the real underlying question here: Should kangaroo provide an IdP? And if so, should it be part of the Authz server, or should it live on its own?