Socket error handling in the client code

[molnarg]

Should be implemented based on this: https://github.com/joyent/node/blob/master/lib/_http_client.js#L232

[jfcalcerrada]

Yes please, or we can't handle TCP socket errors like: http://stackoverflow.com/questions/31775039/how-to-handle-an-etimedout-in-node-js-using-http2