Fix the add stream feature of strm-reset to really work:

Fix the add stream feature of strm-reset to really work:
 - Fix the copy, we can't do a blind copy but must transfer
   the data from the old to the new.
 - Fix the ACK processing so we properly stop retransmitting
   the thing.
 - Fix it so if we get a retran we will properly reply with
   the saved response without doing anything.

MFC after:	1 month