I'm wondering if this should untimely be a collection? If we did this it would mean that extension authors would be able to auto hookup their pieces - I'm thinking something like the ability for a package called Glimpse.Azure.PersistenceStore (which replaces the default in-memory persistence store with a store which writes off to azure) being able to wire-up its own PersistenceStore without the user having to do anything.

There are two possible issues with this:
 - [ ] The users configuration should ultimately override anything else
 - [ ] How does plugin authors code get executed
     - Because of how early this code needs to run, how do plugin authors get their config `func` in place before the `Configuration` is executed