Install desktop entries to datadir/applications/ for each menu item. Please
namespace the filename, as in "vendor-foo.desktop", or use a subdirectory of
datadir/applications/ so you have "vendor/foo.desktop.
So, either writer.desktop, impress.desktop etc. should all become
openoffice.org-writer.desktop and openoffice.org-impress.desktop or they should
all be installed in /usr/share/applications/openoffice.org
Turns out the upstream .desktops are namespaced, as openoffice.org-1.9-etc.
Our's weren't because I short-cutted the OOo install and took the unprocessed
and unprefixed .desktop files. Next spin will be as upstream and name them with
the upstream openoffice.org-1.9 prefix