Update to latest HEAD.
- Add simple way to specify a group of pkgs. for version. BZ 913461.
- Change group install => group upgrade for installed groups. BZ 833087.
- Give more text when telling user about y-c-t, mention history. BZ 974576.
- Fix the tolerant yum.conf text.
- Skip installonly limit, if something has set check_future_rpmdbv. BZ 962757.