Ensures the immutable maps are not copied over in the constructor (more simple and efficient when supported in jclouds)
Prefer Regions to Zones: Rackspace Autoscale
Prefer Regions to Zones: Rackspace Cloud Big Data
Prefer Regions to Zones: OpenStack Marconi
Additional region support in Auto Scale
Prefer Regions to Zones: Rackspace Cloud Queues
More zone reference cleanup