debian/watch or get-orig-source needed

We need a debian/watch file or get-orig-source rule to satisfy Ubuntu's requirements. This needs an actual functioning file or rule, as cantarell is an upstream that publishes tarballs.

Tarballs: ftp://ftp.gnome.org/pub/gnome/sources/cantarell-fonts/0.0/
We also have an import of the cantarell git repo in our code branches. Ideally, we should use that, as the Launchpad builders do not allow access to outside websites.