Merge branch 'devel-2.3'

* devel-2.3:
  QA: Run cluster-verify as part of all instance tests
  QA: Fix typo and add “not”
  ensure-dirs: Speed up when using big queues
  Fix gnt-cluster verify with diskless instances

Conflicts:
	lib/cmdlib.py: Trivial
	qa/ganeti-qa.py: Trivial

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>