req now consumes all the parts of the (multi-part) message in order to preserve the req/rep flow.

Hi Lucas

I was using this program in a project of mine and I noticed that the req/rep pattern broke on multi-part messages, i.e. when the counterparty sends a multi-part rep.

I fixed the issue for my needs and decided to send you a pull request for the changes. Feel free to include the changes upstream :)

Best regards
Gisli