Track last sent seq and read responses until a relevant one is received.
Seems like NEWRULE sometimes (not always) produces two ACKs.
Change-Id: Id650ea4db3a685a2b06d4ab29572ac8d6cfb06fe
Not 100% sure if this is how it's intended to be handled, as the failed
requests seem to produce multiple ACK messages, but at least this fixes
the immediate problem of the printed error message not matching the
request which failed.
Closes#2041
Change-Id: I2a6bf57ce996c134b44d4f3484164a39c68fc93c