add systemd checks

Signed-off-by: Niels Thykier <niels@thykier.net>
c/systemd: Rename and do some "stylistic" changes

Signed-off-by: Niels Thykier <niels@thykier.net>
c/systemd.pm: Correct handling of include

Signed-off-by: Niels Thykier <niels@thykier.net>
c/systemd.pm: Ignore README, skeleton, rc and rcS

Signed-off-by: Niels Thykier <niels@thykier.net>
c/systemd.pm: allow systemctl --daemon-reload lines

Signed-off-by: Niels Thykier <niels@thykier.net>
c/systemd.pm: Ignore symlinks to upstart-job

Signed-off-by: Niels Thykier <niels@thykier.net>
c/systemd.pm: Improve systemctl regex and add line no to tag

Signed-off-by: Niels Thykier <niels@thykier.net>
t(estset): Update to reflect the new systemd check

Signed-off-by: Niels Thykier <niels@thykier.net>
d/changelog: Add changelog entry for the systemd check

Signed-off-by: Niels Thykier <niels@thykier.net>
Merge branch 'systemd-checks'