I can export a Space, and re-import it into another Querki Instance

(User Story, Closed -> Fixed, Priority: High, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Import and Export, Internals
Summary: As the Owner, I should be able to get, eg, a faithful JSON representation of the entire Space. I should be able to turn that into a full copy of that Space later.
This serves two use cases. For users, it provides them with a way to save off a backup of their Space -- especially useful until History gets implemented. For me, it allows me to make a copy of a relevant Space on my development server, so that I can test changes before releasing them to production.