Switch to ZODB.

As part of this, gain some more clarity about the design.
Make list command print more info.
Workaround slugbuilder bug (custom image, run as root).
Use our own copy of strowger.
Rename some classes for clarity.
Use new strowger route SET feature.
Fix deepcopy of service definition.
Fix bug with service def normalizing.
Abstract docker interaction into a backend class.
Begin a serious refactor and tests.

I'm starting to get a bit more happier with this.
Update flynn-postgres to latest refactor.