Allow to specify minimum bytes and maximum wait for simple consumer API

[vincentbernat]

When requesting new messages with the simple consumer API and message is available, by default, the call to messages will return immediatly. If called in a loop to wait for new messages, a user will have to sleep between each call to avoid a tight loop, increasing the latency. The Java API exposes the ability to wait for a minimum of bytes and a maximum of time before returning no record. We expose those knobs in fetch-request and messages.

[pingles]

Awesome, thanks! I've pushed it in the 0.3.3 release on Clojars.

[vincentbernat]

Oh, thanks!