Add RPC style send method.

This plugin is very helpful but it did not offer RPC style messages.  It looks like some code exists but according to the commit logs it was not ready for use.

I need this functionality, so I used the existing functionality provided by RabbitTemplate to send and a receive, and also set the timeout.

This does not satisfy the TODO comments on the existing unused code, but it does provide the basic RPC functionality I required.