Integrates OAuth

Adds library to facilitate oauth dance and acquire token.

Includes middleware to detect when new token is needed, method to get token or dispatch request to middleware, code to handle both sides of the oauth request, and database model to store tokens.

Depends on django's auth-middleware

@kyfantaz 
Ah, OK so I think I was wrong in my thinking (we haven't enabled the admin for any of our apps, so this is new to me).  It looks like enabling the admin is indeed a project-level setting, and your applications essentially register models with the admin.  As long as your'e doing that then where you're declaring the admin urls is fine.