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.
support 'dnf group remove' (RhBug:1013764)
Update some old-style classes.
remove: dnf.yum.rpmsack.RPMDBProblem*.
New version: 0.4.3
build: 0.4.3-1
build: 0.4.3-2
Base.download_packages() must not assume self.progress exists.

Base can only see it when dnf runs from the command line but not otherwise.