Merge branch 'stable-2.4' into devel-2.4

* stable-2.4:
  Add error checking and merging for cluster params
  Clarify --force-join parameter message
  Treat empty oob_program param as default
  Fix bug in instance listing with orphan instances
  Fix bug related to log opening failures
  Bump version for 2.4.1 release
  cfgupgrade: Fix critical bug overwriting RAPI users file

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