Merge branch 'stable-2.6' into devel-2.6

Merge branch 'stable-2.6' into devel-2.6

* stable-2.6:
  verify-disks: Explicitely state nothing has to be done
  Add list of design documents implemented in version 2.6
  Better list of replace-disks arguments + typos fixed
  jqueue: Look at archived jobs when watching
  Show old primary/secondary node on disk replacement
  gnt-instance reinstall: Don't always exit with success
  LUClusterVerify: Ignore /proc/drbd if DRBD is disabled
  Fixed typos in devnotes.rst
  Always_failover doesn't require --allow-failover anymore
  bash_completion: Enable extglob while parsing file
  rpc: Remove duplicated logic, fix unittests
  Annotate disk params on instance_start
  cmdlib: Handle locking.ALL_SET correctly when copying locks

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>