Move virt things into vdsm/virt

Change-Id: Ibdfaefbe8837d2059674fdc4dc83fca431d76f8d
Signed-off-by: Vinzenz Feenstra <vfeenstr@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/21792
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>
Tested-by: Francesco Romani <fromani@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>