To allow in-place replacement of OWSSUPP.dll, we need to be able
to handle the same ProgIDs that it handles, namely:
SharePoint.OpenDocuments and its versions. This allows to use
the SharePoint integration capabilities of LO without the need to
reconfigure SharePoint server's DOCICON.xml (the system would
start the component with same name as MS Office uses).

But this cannot be the default mode, since if MS Office is installed
on the same system, we would hijack the registration, that could be
undesirable.

So, this commit adds an option to use
regsvr32 [/u] /i:Substitute_OWSSUPP path\to\spsupp.dll
to also [un]register SharePoint.OpenDocuments in addition to normal
LOSPSupport.OpenDocuments.

Change-Id: Icc284f9aa8f97ecf04594dd55b99bc1e3d20740d
Reviewed-on: https://gerrit.libreoffice.org/36389Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>