config: extract prepend_installroot() to a public method.
progress: reformat and reword docstrings
progress: add "err" argument to end() callback, merge with failure()

- merged two code paths
- use the new librepo API, where the failurecb arg was dropped, too.
- updated unit tests, it now checks the failure mode too.
always enable LRO_FASTESTMIRROR
tests: skip RepoTest.test_const_install.

activate_sack() fails under the Koji environment as /run/user is not writable
for the metadata lock.
New version: 0.4.2
build: 0.4.2-1
tests: cleanups in support.py
tests: reenable the repo cost testing again.

This takes some refactoring and hawkey needed to improve support for
loading real Yum MD into the testing sacks (see hawkey commit d9d7184).
Fix error handling in Base.downgrade and YumBaseCli.downgradePkgs.
Fix error handling in Base.update and YumBaseCli.updatePkgs.
Fix error handling in Base.remove and YumBaseCli.erasePkgs.
Fix error handling in Base.install and YumBaseCli.installPkgs.
cosmetic: trailing whitespace
packaging: require GTE versions of dependencies.

Requiring the exact version breaks DNF builds in Fedora quite often. After an
unexpected rebuild and version bump of a lib we depend on, projects depending on
DNF fail to build and we are receiving the blame.
tests: add a group that reflects our other testing packages.
groups: add support for 'dnf group info'

Includes verbose mode and UTs.
doc: 'group info'. (RhBug:1013773)
tests: latest libcomps version has a GroupID objects for env.option_ids.
remove: Base._limit_installonly_pkgs().

No use, no love.