Hide Datastores In List With No Active Versions

in a datastore-list operation, for non-admin, filters out
datastores that either have no versions or have no active
versions for non-admin users. admins continue to see all
datastores, active or inactive, in a datastore-list
operation.

Change-Id: Iccaf9ae59469fd0f4cb346ee258d3132eed83660
Co-Authored-By: Andrey Shestakov <ashestakov@mirantis.com>
Closes-Bug: #1290617
Merge "Hide Datastores In List With No Active Versions"
Added Backup/Restore validations

Added checks for backup-create API call to ensure
datastore supports backup strategy
Also for trove-create API call (when restoring from backup)
added checks to ensure that datastore version of backup
being restored matches with datastore version of
instance being created

Change-Id: I9f9cf76ce3d2533612515e6382a184e955e09a32
Closes-Bug: #1285876
Merge "Added Backup/Restore validations"
Merge pull request #2 from openstack/master

pull newest  code