problem: ws_engine doesn't check Sec-WebSocket-Protocol

Solution: Validate Sec-WebSocket-Protocol and make sure ZWS2.0 is one of the protocols

problem: ws_engine doesn't send correct host and path

Solution: extract path and host from the address

Safer regex replace, keeping options like "/Zc:twoPhase-" intact

Relicense: diorcety

grant relicense

Problem: static-only test run fails

Grant by psl-felipefarinon

Received via Github message:

https://github.com/zeromq/libzmq/pull/751#issuecomment-527205167

Solution: add libtestutil.a before libzmq.a in LDADD listings, as the
linker will complain about undefined symbols otherwise

Fixes https://github.com/zeromq/libzmq/issues/3646

Grant by kreuzberger

Received via Github comment:
https://github.com/zeromq/libzmq/pull/1374#issuecomment-527100078

Problem: can no longer send user data from XSUB to XPUB

Solution: fix regression introduced by:
https://github.com/zeromq/libzmq/pull/3168

Correctly fall back to user message if the first byte is neither 0 nor
1, and add a simple unit test

Fixes https://github.com/zeromq/libzmq/issues/3656

Grant by skaller

Received via email, message-id:
B7B30120-05AF-4A53-8023-D9C092DE0873@internode.on.net

Add relicense permission

Relicense permission

Add relicense grant

Grant by dmeehan1968

Received via Github comment:
https://github.com/zeromq/libzmq/pull/1082#issuecomment-526840485

Grants by paddor and mbarbisan

Received by Github message:
https://github.com/zeromq/libzmq/pull/2121#issuecomment-526833407

Received via email, message-id:

CAL4jiWydU5KjXEf1LKKObMgOEfQJVV36zgBY8U5JaXx3mP8c5A@mail.gmail.com

Grants by jbreams and DaiyuHurst

Received as Github comment:
https://github.com/zeromq/libzmq/pull/1451#issuecomment-526832003

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https://github.com/zeromq/libzmq/pull/1283#issuecomment-526831846

RELICENSE: add relicense agreement from msune

Add RELICENSE document for msune contributions, both for:

* marcdevel at gmail dot com
* marc at voltanet io

* Introduce DRAFT zmq_ctx_set_ext() and zmq_ctx_get_ext() methods. Change
ZMQ_THREAD_NAME_PREFIX to allow for non-numeric thread name prefixes.

* UDP engine aborts on networking-related errors from socket syscalls #2862

Problem: appveyor binary archives do not contain import libraries

Solution: include all *.lib files