Add fromAMQP and toAMQP library adapters.

Stream messages to and from AMQP brokers with support for multiple types
of exchanges.  Tested with Ruby publisher, stream parsing in
streamtools, and Ruby consumer on another topic routing key all through
RabbitMQ.
Merge pull request #430 from nickjones/amqp_rebased

Add fromAMQP and toAMQP library adapters.