(*) remove effectivly unused enum constants

(*) tweak the plugins heuristics some more to remove false+ in this enum

(*) twweak the python post-processing step to avoid a KeyError

Change-Id: I2943ec94c00f71dcd049f5c9ef33db259c005ba3
Reviewed-on: https://gerrit.libreoffice.org/63709
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>