downloads: bump number of downloaded files on a skip. (RhBug:1079621)
New version: 0.4.19
build: 0.4.19-1
kernel: remove kernel-source from const.INSTALLONLYPKGS.

Related: RhBug:1062997
Related: RhBug:1079906
refactor: groups: make all commands use _patterns2groups().
refactor: imports order in cli/commands/__init__.py.

Drop a couple too.
doc: cli_vs_yum: we do not partially allow operations that install .srpm. (RhBug:1080489)
doc: cli_vs_yum: typography in bandwidth limiting section.
rename: persistor.Groups -> ClonableDict.
groups: besides installed groups also store persistently the environments.
refactor: RepoPersistor: use the global logger instead of an instance variable.
add dnf.util.partition().
groups: support manipulation with environments (RhBug:1063666)
tests: fix broken InstallMultilib.test_install_src_fails().

artifact from 53a7442.
remove: base.deselectGroup(). it is not used.
fixed: highlight characters broken under py3 (RhBug:1076884)
added logrotate script and ownership of log files to dnf (RhBug:1064211)
removed never executed code based on _ts_saved_file variable
fixed installation of conflicted packages (RhBug:1061780)
api: groups: add comps.Package, add group.package_iter(). (RhBug:1079932)