Merge pull request #571 from hurtonm/master

Add ZAP support
Small fixes to documentation

- REQ and REP sockets don't have HWM issues
- ZMQ_DONTWAIT applies to DEALER and PUSH only
Updated ZAP request for changed protocol draft

- username and password sent as two string frames
- fixed test case to match
Merge pull request #572 from hintjens/master

Updated ZAP PLAIN request to follow latest draft
another iteration on ZMQ_PROBE_ROUTER
now it properly works for ROUTER
Merge pull request #573 from shripchenko/master

another iteration on ZMQ_PROBE_ROUTER
fix memory leak in tempnam() usage
Merge pull request #574 from pijyoi/master

fix memory leak in ipc_listener wildcard
added missing files required to build
Merge pull request #575 from murphybytes/master

Missing files in cmake generated build.
Implement ZMTP/3.0 CURVE handshake