Bug#841670: lintian: Check udev rules and AppStream metadata

[Petter Reinholdtsen <pere@hungry.com>]

[Niels Thykier]
> Hi Petter,
>
> Thanks for working on making Lintian better. :)
>
> I have skimmed though the branch and given a little bit of inline
> feedback. :)

Thank you.  I've adjusted the code based on your feedback, and fixed
broken checks and added some new ones.  A new rebased branch is
available on github.

I hope to get some feedback from the AppStream maintainer to understand
exactly what some of the checks should be looking at, but plan to soon
submit the check with the controls I am confident are correct if he do
not have time to provide input this weekend.

-- 
Happy hacking
Petter Reinholdtsen