Co-maintainers to assist upstreams with their packages in Extras

[Linus Walleij]

I'm happily upstream and maintainer for three packages, libnjb, libmtp and 
gnomad2.

Being part of Fedora has increased quality of all three projects, perhaps 
not much but to some extent. The package review process brings up 
many issues, and I have the privilege to avoid patching and sending 
patches upstream, instead I just FixIt(TM) and release a new version.

When releasing upstream, the fact that the tarball also survives the build 
server environment is a good acceptance test that ensures release quality.

Being both upstream and contributor is quite unproblematic, always was. 
And it's not much work at all, once you get into it.

Linus