Solution: Fix ifdef for expectation of IPC support

Solution: add VS2019 build job

Solution: Use domain sockets instead if available

Solution: move to ip.hpp as zmq::create_ipc_wildcard_address

Solution: Extract TCP/IP loopback variant into zmq_fdpair_tcpip

Change XSUB -> XPUB message processing.

Solution: now if the first frame in a multipart message is not subscribe/unsubscribe,
the rest of the parts are also considered to be not subscribe/unsubscribe.

Fix ZMQ_LAST_ENDPOINT with WS[S] and use it in tests

Solution: bind to wildcard and use ZMQ_LAST_ENDPOINT

Solution: add wss_address_t subclass of ws_address_t to override the
to_string method

Solution: remove the path from the address when resolving

Solution: use the correct address class when resolving

Problem: static libs are generated without given basename

Change XSUB -> XPUB multipart message processing.

Now only the first part in a multipart message will be treated as subscribe/unsubscribe.
The rest will be considered user messages regardless of the first byte.

Allow library output name to be changed externally

Remove the superfluous build requirement of libsodium-devel

problem: test_wss_transport keys expired

Solution: generate new keys that last for 100 years

Problem: test_pair_tcp_cap_net_admin requires sudo but is enabled by …

Problem: WSAEventSelect checks for FD_OOB, but select does not

WSAEventSelect is used on Windows (when select is the polling method)
only if waiting for more than one socket family, excluding IPv4/6.
It is then passed FD_OOB, which means it can be woken by OOB messages,
but select later on never checks for it.
Remove FD_OOB as it's not actually used for anything.

Fix typo in email address

Problem: Poller example has wrong argument order

Solution: flipped arguments in example

Solution: add an option to enable it, and default to false. Enable it in
the CI so we don't lose coverage, as it works on Travis.

Fixes #3725

Problem: ipc transport not supported under Windows

Solution: call tune_socket only if connect was successful

Solution: implement support

Add a few quality of life improvements to the Android build scripts