docs: publish thorough and varied benchmarks

To counter this nonsense:

http://www.bravenewgeek.com/dissecting-message-queues/

More importantly, because it would be interesting to publish benchmarks that more accurately represent real production topologies, in the spirit of:

https://engineering.linkedin.com/kafka/benchmarking-apache-kafka-2-million-writes-second-three-cheap-machines

and

http://blog.pivotal.io/pivotal/products/rabbitmq-hits-one-million-messages-per-second-on-google-compute-engine