Sebas rotation fixes

    CentOS 5/6 compatible back up rotation and more
    
    Changelist:
    
    - added auto qpress installation to installer
    - Installer asks  for preferred backup time and configures a cron job
      under root's tab accordingly (full backup)
    - rotate_backups function uses mtime instead of newermt (so it works
      on cent 5/6)
    - for easy app manager integration full & inc actions spit out backup
      status to $backup/directory/backup.status:
    
    status=0 after a successful run
    status=1 after failure
    
    I use a script monitor on fgo,, which checks the age of the
    backup.status file (to make sure backups are running) and then use
    app manager thresholds to alert if the file is stale or if it
    contains status=1.
    
    IMPORTANT:
    Since rotate works differently, configuration file surrogate.conf
    must be changed too:
    instead of descriptive vars for retention, use days:
    
    daily_retention="7"
    weekly_retention="28"
    monthly_retention="180"