Dealers, Routers, Restructures, oh my!
To clean the documentation, this release moves all the socket wrapper types into a single file. It also moves to make MultipartSink and MultipartStream use the zmq socket logic from MultipartRequest and MultipartResponse from the async::future module. This simplifies the library and ensures any change to sending or receiving zmq messages affects streams and futures.
This release also brings the Dealer and Router socket types, to allow creation of brokers on the Tokio event loop.