Introduce OpenID sub-app.
[OpenID] initial login support.
[OpenID] Initial endpoint discovery support.
[OpenID] initial request/response support.

For now, it's just automated associating + rejecting check-id requests.
[OpenID] Introduce Django/DB backend for python-openid store.

This allows us to nicely store associations and nonces through django's
database backend without hacking SQL ourselves.
[OpenID] Support minimal site auth.
[OpenID] Explicitly note that login is requested by OpenID request.
[OpenID] Fix timezone support in DjangoDBOpenIDStore.
[OpenID] support timezones properly in stored datetimes.
[OpenID] Build absolute endpoint URI from request.
[OpenID] Re-tab templates.
[OpenID] Allow cancelling request on login page.
[OpenID] Enable Return-To trust checks.

Just display the results for now.
[OpenID] Pre-fill login form with requested username.
[OpenID] send proper identity in response for logged in user.
[OpenID] remove unnecessary trust_root-return_to check.

The check is done internally by the library already, so there's no point
in repeating it. And it results in fatal protocol error.
Merge remote-tracking branch 'origin/master' into openid-week2
Disable OpenID application.

The code from it will be moved into accounts app.
Move OpenID store model to accounts app.
Re-enable a minimal OpenID endpoint facility.