vos: allow releases without offline time

vos: allow releases without offline time

allow releases using dumps to clones to avoid offline time

Reviewed-on: http://gerrit.openafs.org/6254
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Alistair Ferguson <alistair.ferguson@mac.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>
(cherry picked from commit 13a4f2b18bb84d05773529a794371d29f64570ab)

Change-Id: Iec0f2d882dc2ac9a11ed4ca282cb2424db052803
Reviewed-on: http://gerrit.openafs.org/6765
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Alistair Ferguson <alistair.ferguson@mac.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>