WIP: Support freedesktop.org GitLab/Bugzilla
This is what I've been using to do the import into fd.o's GitLab instance, though per discussion with @csoriano it really needs to be rebased on top of alternative-master, which I'll do ASAP and publish after some testing. Thought it might be better to get some of this stuff pushed out as early as possible though.
The commits from @bilboed were picked out of his branch and separated into individual commits.