This commit adds 'openstack share adopt' and 'openstack share abandon'
commands, that implement the same functionality as 'manila manage' and
'manila unmanage' commands
Usage:
openstack share adopt <service-host> <protocol> <export-path>
openstack share abandon <share>
Partially-implements bp openstack-client-support
Change-Id: I39919d38854387af21da410849905698ad261e9f