Support for extra packages

When you add new dependency you can use new options --extra-packages to
install rpms before you package katello. You can specify more of them as
multiple -e param. You can specify a package as an URL (e.g. from koji).
Make vim usable on dark console
minor improvements
Merge branch 'ares-master'

* ares-master: (3 commits)
  minor improvements
  ...