cron and systemd adjustments
    
    - Move cron to a separate file, and require crontabs (RHBZ #947047).
    - Update for systemd (RHBZ #947047).
    
    Thanks Jóhann B. Guðmundsson <johannbg@fedoraproject.org> for both
    fixes.
    
    - Replace tab with spaces to satisfy rpmlint.