Add versionedobjects abstraction layer to services. Distinguish time
zone aware DateTime fields. The object derives from
CinderObjectDictCompat, so it supports both object (obj.prop) and dict
(obj['prop']) syntax to access properties. Complete move to object
notation will be made in a follow up clean up patch.
Co-Authored-By: Michal Dulko <michal.dulko@intel.com>
Change-Id: I09f593f9f9aa8befa40d989b731159b78a429071
Partial-Implements: blueprint cinder-objects