Fix wrong cache directory path used to clean up binary cache
Adds new motd emitter for dnf-automatic (RhBug:995537)
Run tests with C locales.

This fixes tests failing on translated messages.
groups: searches also within localized names (RhBug:1150474)
base: package_upgrade does not reinstall or downgrade (RhBug:1149972)
base: package_downgrade prints message on failure
base: package_install allows install different arch of installed package
base: package_reinstall works only with the same package versions
doc: swap command alternative mentioned (RhBug:1110780)
fixed error summary traceback (RhBug:1151740)
tests: removed mock patch for _, P_
install: allow installation of provides with glob (Related:RhBug:1148353)
new authors added
cli: _process_demands() does not respect --caheonly (RhBug:1151854)
base: output a whole list of installed packages with glob pattern (RhBug:1163063)
bash-completion: fix completing  without dnf-plugins-core (RhBug:1151231)

dnf list is printing some info which we should not parse (especially
with debug - `Cleaning` string). We want use only packages from output.
Let's find string `Available Packages` and print all packages before
next info string `Cleaning`. If user will have some custom plugins which
will modify `list` command - completion will be break, but we can
guarantee that with `dnf` and with/without dnf-plugins-core it will work
OK.

Reference: https://bugzilla.redhat.com/show_bug.cgi?id=1151231
Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>