Ticket 54 - Move job done callback
    
    Bug Description:  In the case we don't clean the fd, we may want to allow the
    user to do so.
    
    Fix Description:  To facilitate this, the job done callback should be AFTER
    the fd free code, allowing the user to clean it up if they wish.
    
    https://fedorahosted.org/nunc-stans/ticket/54
    
    Author: wibrown
    
    Review by: nhosoi (Thank you!)