packaging: engine-backup: Allow multiple scopes
packaging: engine-backup: Allow multiple scopes

Allow passing '--scope=' more than once.

Also fix some issues related to backing up or restoring with different
or multiple scopes.

Change-Id: I331900e5ca92bd91196189cf584694c64bddf240
Bug-Url: https://bugzilla.redhat.com/1208122
Signed-off-by: Yedidyah Bar David <e7f2f616ce8817ad893bbeaad3e942e94c69d323@redhat.com>

yingyun001/ovirt-engine,zerodengxinchao/ovirt-engine,eayun/ovirt-engine,yingyun001/ovirt-engine,yapengsong/ovirt-engine,walteryang47/ovirt-engine,walteryang47/ovirt-engine,walteryang47/ovirt-engine,OpenUniversity/ovirt-engine,zerodengxinchao/ovirt-engine,walteryang47/ovirt-engine,eayun/ovirt-engine,eayun/ovirt-engine,OpenUniversity/ovirt-engine,yingyun001/ovirt-engine,eayun/ovirt-engine,OpenUniversity/ovirt-engine,zerodengxinchao/ovirt-engine,zerodengxinchao/ovirt-engine,yapengsong/ovirt-engine,yingyun001/ovirt-engine,eayun/ovirt-engine,yingyun001/ovirt-engine,yapengsong/ovirt-engine,yapengsong/ovirt-engine,zerodengxinchao/ovirt-engine,OpenUniversity/ovirt-engine,walteryang47/ovirt-engine,yapengsong/ovirt-engine,OpenUniversity/ovirt-engine