Ticket 48957 - set proper update status to replication
     agreement in case of failure
    
    Bug Description:  If a replication agreement fails to send updates it always returns
                      a generic error message even though there are many ways it could be
                      failing.
    
    Fix Description:  Set a proper error message when we fail to update a replica.  Also made
                      all the messages consistent in format, and added new response strings
                      for known errors.
    
                      Also fixed some minor compiler warnings.
    
    https://fedorahosted.org/389/ticket/48957
    
    Reviewed by: nhosoi(Thanks!)