Update to latest oslo rootwrap

Update Cinder rootwrap to the latest from oslo-incubator. This allows
to import the latest filters and bugfixes, in preparation for the
havana release.

All the changes are coming directly from the Oslo "rootwrap" module
sync.

Change-Id: Ie26562b9e934d48275dbd3993af1a8d0bdde77d1
Merge "Update to latest oslo rootwrap"