Do not retry CONNECT packets

[icraggs]

In section 4.4.2 I have included CONNECT and AUTH in the list of packets to be retried. Simon made a comment that the packet id should be incremented every time - that is, the CONNECT packet should not be retried.

After thinking about it, I think this is correct. I need to make the changes.

[icraggs]

Added these two conformance clauses to 4.4.2:

CONNECT and AUTH packets expect a response but MUST NOT be retried.
The connection sequence CONNECT, zero or more AUTH Packets then CONNACK MUST be completed without retries.

[lenzarda]

@icraggs I fully agree