* Command names changed from null terminated to length-specified
* Command frames use the correct flag (bit 2)
* test_stream acts as test case for command frames
* Some code cleanups
- designed for TCP clients and servers
- added HTTP client / server example in tests/test_stream.cpp
- same as ZMQ_ROUTER + ZMQ_ROUTER_RAW + ZMQ_ROUTER_MANDATORY
- includes b893ce set ZMQ_IDENTITY on outgoing connect
- deprecates ZMQ_ROUTER_RAW