Replace _parse_yum with calls to repoquery.

This fixes #4998. It also introduces a new dependency for distros which
use YUM: yum-utils. This package is in the base repo so it is a painless
dependency to add.
Add dependency on yum-utils

This adds the depedency on yum-utils to to the RPM spec, as necessitated
by the change made to yumpkg5.py in 8f77216.