0MQ version 4.2.1 stable, released on 2016/12/31

• New DRAFT (see NEWS for 4.2.0) Socket Monitor events:
  • ZMQ_EVENT_HANDSHAKE_SUCCEED
  • ZMQ_EVENT_HANDSHAKE_FAILED
    These events trigger when the ZMTP security mechanism handshake is
    completed. See doc/zmq_socket_monitor.txt for more information.
• New DRAFT (see NEWS for 4.2.0) Context options:
  • ZMQ_MSG_T_SIZE
    See doc/zmq_ctx_get.txt for more information.
• Fixed #2268 - improved compatibility with mingw32
• Fixed #2254 - ZMQ_PUB compatibility with libzmq 2.x broken
• Fixed #2245 - added support for VS2017, Windows SDK 10.0.14393.0, toolset v141
• Fixed #2242 - file descriptors leaks on fork+exec
• Fixed #2239 - retired poller item crash from reaper thread
• Fixed #2234 - improved compatibility with AIX 7.1
• Fixed #2225 - cannot pick select for poller
• Fixed #2217 - CMake build uses library version as the ABI version
• Fixed #2208 - added support for ZMQ_TOS on IPv6
• Fixed #2200 - no documentation for ZMQ_SOCKS_PROXY
• Fixed #2199 - no documentation for zmq_curve_public
• Fixed #2196 - fixed build and runtime errors on kFreeBSD