openid_provider: Include a link to the user's OpenID in the index
openid_provider: Fix redirect after a user logs in

The default URL /accounts/profile doesn't exist. Just send them back to
/.
Add basics of a frontend system

This will in future be the only system that has a public IP, and will
proxy requests to the correct instances according to the subdomain and
possibly path of the request.
Flesh out README a bit.
openid_provider: Add Cherokee and uWSGI to serve the application