Do the needful to move Zone Exports to an asynchronous resource in the
v2 API, as discussed at the Austin 2015 summe mid-cycle
* Make designate-zone-manager an RPC service, with a read-only connection
to the database
* Add a 'location' column to the zone_tasks table that stores a location
(swift, URI) that is used to determine where the export will be made
available to the user
* Add all the infrastucture to make zone export resources live (objects,
central, storage methods)
* Add a quota on the size of allowed synchronous exports
* Tests, docs
THIS DOES NOT IMPLEMENT
* Zone exports to Swift
* Debateable: See the note in zone_manager/service.py about how the configuration
and determination of future swift exports will work.
ApiImpact
Blueprint: async-export
Change-Id: I1c168b10358164c3ca5be986b4d615df71062851
50d1b1553e