update the plugin with lessons learned from the mergeclasses plugin and
re-run it

Change-Id: I9d622eb3d05fceaf8fa764c533c8fa5dfb4c7711
Reviewed-on: https://gerrit.libreoffice.org/20015Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>