Merge branch 'stable-2.9' into stable-2.10

* stable-2.9
  Bump revision for 2.9.1
  Update NEWS and schedule release for 2.9.1
  Fix retrieval of xen command in class method
  Fix docstring for ganeti.storage.filestorage_unittest.py
  Undo revision bump
  Postpone release of 2.9.1
  Revision bump for 2.9.1
  Update NEWS for 2.9.1 release
  Readd nodes as online
  When verifying BRBD version, ignore missing values

* stable-2.8
  Version bump for 2.8.2
  Update NEWS file for 2.8.2 release
  DRBD: ensure peers are UpToDate for dual-primary

Conflicts:
    NEWS: trivial
	configure.ac: ignore version bump

Signed-off-by: Thomas Thrainer <thomasth@google.com>
Reviewed-by: Hrvoje Ribicic <riba@google.com>