Email notifications for reproducible build status change

[intrigeri]

Hi,

the reproducible builds people provide an option to notify maintainers
when the reproducible build status of their package changes (e.g.
reproducible → non-reproducible). At DebConf, I quickly surveyed a few
of you and everybody was OK with asking to get these notifications.

So I did that. If we ever want it to stop, or need to complain about
things not working as expected, one needs to talk to Mattia Rizzolo
(mapreri on IRC).

Note that newly introduced packages won't be picked up by this system,
and there are a few more implementation gotchas. IMO it's no big deal
at the moment, and having working notifications for 99.9% of our
packages will be better than nothing, until the reproducible builds
people fix these problems (which they have other, stronger incentives
to).

Cheers,
-- 
intrigeri