instead of overloading the nMemberId field
and thus fix various places that were effectively setting the METRIC
flag and causing a warning in SvxUnoConvertToMM

And fix bug in
    sw/source/core/unocore/unomap.cxx
where the PropertyAttribute::READONLY was in the wrong place,
ever since
    commit 84a3db80
    Date:   Mon Sep 18 23:08:29 2000 +0000
    initial import

Change-Id: Ifc2bf56709f19aea75300b2fda62ce551efc26af
Reviewed-on: https://gerrit.libreoffice.org/48950Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Noel Grandin <noel.grandin@collabora.co.uk>