Ticket 48336 - setup-ds should detect if port is already defined
    
    Bug Description:  Previously setup-ds.pl could not detect if a port was defined
    in selinux policy or not.
    
    Fix Description:  This adds a set of selinux helpers that can query selinux port
    in policy. Using these, setup-ds.pl can now make better decisions about whether
    to label ports, or if they should be removed from policy during removal.
    
    https://fedorahosted.org/389/ticket/48336
    
    Author: wibrown
    
    Review by: vashirov and nhosoi (Thank you!)