When resource audit logging is enabled STOMP is completely inoperable
due to an NPE during the protocol handshake. Unfortunately the failure
is completely silent. There are no logs to indicate a problem.
This commit fixes this problem via the following changes:
- Mitigate the original NPE via a check for null
- Move the logic necessary to set the "protocol connection" on the
"transport connection" to a class shared by all implementations.
- Add exception handling to log failures like this in the future.
- Add tests to ensure the audit logging is correct.