Some new tests that cover some AMQP credit handling scenarios. Test
case 'testCloseBusyReceiver' currently fails due to being dispatched a
duplicate message.
Two new tests that acquire messages inside a TX and manage their
settlement and retirement in differing ways, one test works the other
'testReceiversCommitAndRollbackWithMultipleSessionsInSingleTXNoSettlement'
fails due to messages that were committed being redelivered to the
client unexpectedly.
Refactor the AMQP Message transformers both for better performance and
also to fix a number of issues with the transformers creating inbound
and outbound messages with incorrectly mapped values or extra data
appended where it should not be.