Address bug in which delivery tag returns as buffer, preventing lookups
from _unAcked table.

We were unable to get `publish` methods to return callbacks. Examination
of the code revealed that the `deliveryTag` is returned as a buffer,
while the `_unAcked` table is keyed by a string representing
`_sequence`. This caused `_unAcked` callbacks to be unretrievable when
the publication event was acknowledged.

The "fix" in this code at least identifies the error. The approach is to
read the last 4 bytes of the buffer. Note that the buffer is 8 bytes,
meaning we are ignoring the first 4 bytes. However, this is seeded with
the `_sequence` value (an integer) at send time, and therefore will
never be larger than 4 bytes anyway.
Add the option to reject and requeue a message with shift()
Merge pull request #207 from bausmeier/shift-requeue

Add the option to reject and requeue a message with shift()
Added support for changing the auth mechanism.
Merge pull request #208 from bakkerthehacker/master

Added support for changing the auth mechanism.
Implemented support for SSL.
Added rejectUnauthorized and changed ssl option names.
Merge pull request #209 from bakkerthehacker/master

Implemented support for SSL.
Merge pull request #206 from SkynetInc/master

Address bug in which delivery tag returns as buffer, preventing lookups from _unAcked table.
Fixed queue shifting options that were removed with SSL changes.
Merge pull request #212 from bakkerthehacker/master

Fixed queue shifting options that were removed with SSL changes.
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...
Merge pull request #1 from postwait/master

Merge in latest