Generalize how configurations are saved to allow for multiple backends

To make lernid more widely deployable outside Ubuntu, it would be useful to generalize the configuration storage so that CouchDB was not strictly needed (but still available for individual users to use).

I've already implemented a local configuration file store drop-in replacement for CouchDB inside Lernid for use in Fedora. The goal being to allow users to use lernid without the complexity and system resource expense of having to install CouchDB. But then if the system has CouchDB available to seemlessly export the local configuration store settings into CouchDB without user intervention. The point being to make CouchDB an optional feature that users can choose to take advantage of while keeping lernid's core functionality in tact.

But if you are interested. I would like to find a solution that is more general, allowing for the development of common storage backends(including but not limited to CouchDB, DConf, sqlitedb) and a facility by which users could import/export across multiple storage backends with minimal effort.

We might even be able to craft such a solution in a way that it becomes a standard quickly snippet so all quickly developed applications can take advantage.

-jef