Since deliverTag became a buffer publish acknowledgements from exchanges opened with confirm=true were not being recognised.  Pull request 206, which has been accepted, only addressed 1 of the 3 scenarios required.  This commit addresses the other 2 scenarios which were originally still trying to compare an integer with a buffer.
Merge pull request #213 from redbadger/issue-206

Since deliveryTag became a buffer publish acknowledgements from exchanges...