Milestone rpm_check vs. depsolve dead end

This is mostly somewhere to put all the kmod and Xz tickets.

In theory we could fix them eventually, but it's a non-trivial corner case.

Xz == rpmlib deps. ... latest upstream now outputs a message. It might even be worth outputting the "current rpmlib provides" ... if someone really cares we could download the latest version of rpm and look in the header to see if it fixes the problem.

kmod == kernel modules nightmare of the week, this will probably never be fixed outside of RHEL and using a small number of kmod packages.