config-package-dev should install Lintian override for package-contains-empty-directory for DEB_REMOVE_FILES

[geofft]

DEB_REMOVE_FILES operates by ensuring that /usr/share/packagename exists, and diverting the file in question there on install. For a couple of our packages, we don't otherwise use /usr/share/packagename, which is causing a  package-contains-empty-directory Lintian warning. Since config-package-dev knows it is likely to create an empty /usr/share/packagename directory when DEB_REMOVE_FILES is in use, it should automatically install the override in that case.

[geofft]

It looks awfully annoying for a Debhelper plugin/command to add a Lintian override, since dh_lintian just drops a single lintian-overrides file in place. We could attempt to sequence ourselves after dh_lintian and append to that file, I guess? Or we could ask dh_lintian to provide an interface.