Problem: autotools build broken

Solution: fix directory reference

Support epoll polling under Windows with wepoll

Problem: test_context_socket is not thread-safe

Solution: skip tests than can never succeed with MSVC

Problem: prepared Visual Studio solution files are hard to maintain and redundant with CMake builds

Solution: use regular zmq_socket instead in thread functions

Solution: declare them as deprecated

Solution: increase timeout

Solution: disable test cases

Solution: use unity mechanism for ignoring with message

Solution: increase timeout, remove timeout settings for unsupported poll poller

Solution: add diagnostic output

Solution: use TEST_ASSERT_FAILURE_ERRNO

Solution: add epoll build job

Solution: Use wepoll on Windows

Solution: import wepoll 1.5.0 source

Problem: test_inproc_connect not using test framework

Improve socket inheritance handling

Solution: migrate to unity

Solution: create sockets with WSA_FLAG_NO_HANDLE_INHERIT

Solution: extracted make_socket_noninheritable function

Solution: make error handling consistent and use retired_fd to remove code duplication

Allow EBADF on iOS #3046

Migrated some more tests to unity and fixed some more code style issues

Split poller config and disable 'poll' poller on Windows for I/O thread polling

Solution: add const

Solution: removed

Solution: add alloc_assert

Solution: use API_POLLER=poll instead of POLLER=poll

Problem: API poller cannot be set independently from I/O thread poller, poll I/O thread poller broken on Windows

Solution: change platform definitions to separate API poller from I/O thread poller, disallow configuring poll I/O thread poller on Windows

Solution: migrate to unity

Solution: insert some sleeps to remedy timing dependencies

Solution: migrate to unity

Solution: migrate to unity

Solution: added test case, reproduces the likely cause for #3107

* Update zmq_connect documentation to mention issue of multiple connects to the same endpoint

Fix some more code style issues

Solution: replace by C++-style casts

Solution: add no-return attributes