Support for streams

[ebdrup]

Hi when doing a request with for example the request module, sometimes you want to do the request as streams and pipe the response. Meaning that there is no callback, instead you have to watch for the stream returned by request.get being destroyed (maybe with an error).

It would be awesome if levee supported streaming.

Basically breaker.run will return a stream and you have to attach to .on('close', ...) and .on('error', ...), etc. for breaking/timeout etc.

The module end-of-stream would be handy for this.

[tlivings]

I've been working on optional callbacks and return values. I actually have a PR open for returning result from underlying function call, but optional callbacks will likely require a new API.