When deleting a master, try to prevent orphaning other servers.
    
    If you have a replication topology like A <-> B <-> C and you try
    to delete server B that will leave A and C orphaned. It may also
    prevent re-installation of a new master on B because the cn=masters
    entry for it probably still exists on at least one of the other masters.
    
    Check on each master that it connects to to ensure that it isn't the
    last link, and fail if it is. If any of the masters are not up then
    warn that this could be a bad thing but let the user continue if
    they want.
    
    Add a new option to the del command, --cleanup, which runs the
    replica_cleanup() routine to completely clean up references to a master.
    
    https://fedorahosted.org/freeipa/ticket/2797