Merge pull request #722 from ricnewton/master

Fix test warnings
Fixed ref to zmq_socket_monitor
Merge pull request #723 from hintjens/master

Fixed ref to zmq_socket_monitor
Renamed test_router_raw_empty to test_stream_empty

* The ZMQ_ROUTER_RAW API was deprecated in favor of ZMQ_STREAM
* Same issue hit router.cpp, which I've fixed
Merge pull request #724 from hintjens/master

Renamed test_router_raw_empty to test_stream_empty