Fix for:
In systemd-services.trigger line 14:
systemctl $cmd $service
^--^ SC2086 (info): Double quote to prevent globbing and word splitting.
^------^ SC2086 (info): Double quote to prevent globbing and word splitting.
Let's put everything systemd related in an extra-repos directory, so it
is clear that the packages from here will end up in a separate, optional
binary package repository.