Ticket 47803 - syncrepl crash if attribute list is non-empty
    
    Bug Description:  if the list of requested attributes in a persistent
    			sync repl request was set, the server could
    			crash after a modify operation which should
    			send an entry
    
    Fix Description:   the reason for the crash was that the list of requested
    			attributes was freed when the original search
    			operation was completed. In the persit phase this
    			list was still accessed.
    			To fix it, a copy of the orignal op had to be used
                            and the list of requested attr duplicated and set
    			in the copy of the op.
    			unfortunately a reference to the original op is
    			still needed as the disconnet code sets the abandonned
                            flag to the original op
    			To be able to duplicate an operation, some methods to get
    			and set operation attributes had to be provided
    
    https://fedorahosted.org/389/ticket/47803
    
    Reviewed by: RichM. ThanksRichM. Thanks