Currently, if fail2ban is killed (or crashes), its status will be
reported by '/etc/init.d/fail2ban status' as 'running' even though it
is not. Attempting to restart the service also fails, because Gentoo
unsuccessfully tries to stop the service.
By using start-stop-daemon and providing a pidfile, Gentoo will
instead report the status as 'crashed' and allow the service to be
restarted as normal.