add db migration to drop columns will be moved to sta.conf.
change sta.conf structure to localize each driver specific configuration.
update `POST /volumes` endpoint to adapt new volume model association.
mussel: add "volume create" sub command.
sta: update backend to create/delete zfs volume.
dcmgr: instance boot/terminate for iscsi volume.
dcmgr: fix `PUT /volumes/vol-xxxx/attach,detach` endpoint.
mussel: add `volume attach`/ `volume detach` subcommands.
hva: add RHEL6 specific change and adapt for storage data model changes.
dcmgr: allow volume attach/detach for halted instance.
sta: rename LinuxIscsi to Tgt.
mussel: add "volume backup" subcommand.
sta: add backup_volume task.
hva: fix method error at conf validation.
sta: show loading driver name at startup.
hva: fix NameError code issues.
hva: add hypervisor driver specific local_store conf section.
Merge branch 'master' into feature-shared-vol
fix syntax break at merge.
hva: disable auto mount after OS reboot for iscsi volume.