Merge branch 'devel-2.4' into stable-2.4

* devel-2.4: (23 commits)
  Fix pylint warnings
  Change the list formatting to a 'special' chars
  Add support for merging node groups
  Add option to rename groups on conflict
  Fix minor docstring typo
  Fix HV/OS parameter validation on non-vm nodes
  NodeQuery: mark live fields as UNAVAIL for non-vm_capable nodes
  NodeQuery: don't query non-vm_capable nodes
  Remove superfluous redundant requirement
  Don't remove master_candidate flag from merged nodes
  Use a consistent ECID base
  listrunner: convert from getopt to optparse
  listrunner: fix agent usage
  Revert "Disable the cluster-merge tool for the moment"
  Fix cluster-merging by not stopping noded
  Fix error msg for instances on offline nodes
  Minor reordering to match param order
  cluster verify and instance disks on offline nodes
  Cluster verify and N+1 warnings for offline nodes
  Handle gnt-instance shutdown --all for empty clusters
  Use gnt-node add --force-join to add foreign nodes
  Add --force-join option to gnt-node add
  Fix iterating over node groups

Of the above commits present in the devel-2.4 branch, only the “Add
--force-join option to gnt-node add” is a potential issue, but this
has been QA-ed successfully. The other fixes are split in three
groups:

- non-core changes (cluster-merge, listrunner)
- trivial fixes (docstrings, etc.)
- bugs that we want fixed

As such, instead of cherry-picking only individual patches, I propose
that we unify stable and devel 2.4 and make a new RC out of the
result.

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

diff --cc lib/cmdlib.py
Simple merge