[WIP] Implement support for networking-as-a-service (aka OpenStack Neutron)

This is a WIP PR. Feel free to review but do not merge it just yet. When it is ready for merge all "WIP" mentions will be removed from it.
Yeah, I think that's a good compromise. So a class docblock should document (in 2-3 sentences) was the API resource does; and how the class performs that representation.