(20096) Support systemd on Fedora 15 and up

Add a check to see if running Fedora 15 in order to use init scripts
provided by systemd. This adds compatibility for systemd on Fedora,
which currently returns an incorrect failure message when persisting
rules.
Merge pull request #145 from ecbypi/ticket/20096-fedora-systemd-support

(20096) Support systemd on Fedora 15 and up