AMQP-348 Support Consumer Arguments

RabbitMQ 3.2 introduced consumer priority...

http://www.rabbitmq.com/blog/2013/12/16/using-consumer-priorities-with-rabbitmq/

* Add consumerArguments property to SMLC
* Add priority to listener element
* Update to latest Rabbit Client - required fix to test case for PossibleAuthenticationFailureException because it now has ambiguous constructors.