Include a working settings file

I know you're not checking in your settings file because it includes production information, but it would be nice to include one in the repo so anyone can get started quickly.

To help with this I'm introducing a "settings_local" file, where production and sensitive information can be added. The project will import settings_local if it exists, and suppress the import error if it does not (so you don't have to make one).

I also added a settings.py file as a starting point.  It uses reasonable defaults (like sqlite3) and configures absolute paths using __file__.