Solution: rework the bash test to avoid build failures as intended
and make it an easier one-liner

Solution: install asciidoc and xmlto in the libsodium build run, since
it already refreshes APT to download other packages, so the delay is
smaller

Solution: use packages on Ubuntu and brews on OSX. The packages and
the brews are always kept up to date, so it's no use to rebuild the
libsodium stable branch manually everytime.

Solution: Revert "Problem: Travis CI OSX builds are broken"

This reverts commit 531b3bf7.

Solution: narrow down the matrix to install valgrind and lcov only
for the test runs that use them.
CMake is part of the default image so no need to install it at all.

Solution: add it to the list

Solution: if available, call socketpair with SOCK_CLOEXEC flag to
make the process close the socket on fork+exec

Solution: if available, use eventfd with EFD_CLOEXEC flag to make
the process close the socket on fork+exec

Solution: if available, use epoll_create1 with EPOLL_CLOEXEC flag to
make the process close the socket on fork+exec

Solution: add paragraphs to zmq_get/setsockopt man pages

Solution: add manpage

Solution: add a comment as it's easy to miss and very tempting to
"optimize"

Mingw32 Compile

Problem: Duplicated code

Solution: set_curve_key method in options_t struct with little
improvement in switch-case block

Problem: contributing guidelines unclear for new devs

Solution: port Github PR template from CZMQ

Solution: Revert "Problem: Duplicated code"

This reverts commit 022eeaf3.

Problem: Duplicated code

Solution: set_curve_key method in options_t struct with little
improvement in switch-case block

* Fixed handling of WSAEWOULDBLOCK to be generic

I don't know what was the intention of this early if statement but
now this is properly evaluated in wsa_error_no function if this is
performance issue I suggest moving evaluating this error code to the
beginning of wsa_error_no.

* Fixed handling of WSAEWOULDBLOCK to be generic

Introduced default pointer to const char * and overrides this as NULL
if function is called by zmq::wsa_error()

* Fixed handling of WSAEWOULDBLOCK to be generic

Introduced default pointer to const char * and overrides this as NULL
if function is called by zmq::wsa_error()

zmq_poll: only compare FD when neither item is a zmq socket

fix bug zmq4.x PUB msg to ZMTP1.0 SUB server

Problem: no mixed FD and zmq socket zmq_poll test

Solution: add one

misuse of 'close'

use 'pollset_destroy' instead of 'close' to release pollset_fd

Problem: check for item.fd causes zloop_poller regression

Solution: fix the check for the socket.
This regression happens when using zloop with zmq_pollitem_it with
only file descriptors registerted through zloop_poller.

"%" -> '%'