Solution: add missing includes

Solution: ifdef is_ipv6_available to always return false if building
on Windows XP, as it doesn't support the needed standard libc
functions

This reverts commit 9adf20aa.

This is required as zmq_ctx_new calls WSAStartup. Without that the IPV6
socket creation always fails.

Solution: correct path is ../src/windows.hpp. Also added automatic linking
of iphlpapi library if required and using MSVC

Solution: before including internal headers, include platform.hpp
so that the build time options are correctly applied to the included
headers.

Solution: add helper function is_ipv6_available to testutil.hpp to
test if IPv6 is available on the building platform.
This function will try to open and bind a socket to ::1:*, as it's
the ultimate way of knowing if, at least on the loopback, IPv6 is
enabled.

Solution: increase SETTLE_TIME from 50ms to 300ms to avoid failing on
slower environments like through Valgrind on slow VMs.

Solution: include pthread.h in testutil.hpp, removed from
test_shutdown_stress_tipc in an earlier commit

Solution: it's a lot of work to define the tests in project.gyp
so I did this using gsl to generate the JSON, from a small XML
list of the test cases.

To keep this, and the hundreds of .mk files, away from the root
directory, I've moved the gyp files into builds/gyp, where you
would run them.

It all seems to work now. Next up, OS/X and Windows :)

Solution: update to 2016

This is due to the mangled include of platform.h, which was to make
CMake happy.

Solution: in CMakeLists.txt, define USING_CMAKE and then look for
platform.h in current directory if that is defined, else look in
../src/ as one would expect.

Solution: added to test_stream.cpp

It's nice to be able to disable libzmq's internal timeout when there's
another timeout in the test runner being used which gives nicer error
messages.

Of course people still "can" distributed the sources under the
LGPLv3. However we provide COPYING.LESSER with additional grants.

Solution: specify these grants in the header of each source file.

Solution: raise timeouts from 100-150 msec to 250 msec

Symptom is that ZMQ_STREAM sockets in 4.1.0 and 4.1.1 generate zero
sized messages on each new connection, unlike 4.0.x which did not do
this.

Person who made this commit also changed test cases so that contract
breakage did not show. Same person was later banned for persistently
poor form in CZMQ contributions.

Solution: enable connect notifications on ZMQ_STREAM sockets using a
new ZMQ_STREAM_NOTIFY setting. By default, socket does not deliver
notifications, and behaves as in 4.0.x.

Fixes #1316

Solution: update for 2015

Fixes #1320

Solution: increase settle time for bind/unbind tests

Updated:
   tests/testutil.hpp: Add signal(SIGPIPE, SIG_IGN) to
        setup_test_environment(), on z/OS (__MVS__)

Users who need e.g. zmq_curve_keypair() have to remember to include
zmq_utils.h, which is counter-intuitive. The whole library should be
represented by a single include file.

Solution: merge all contents of zmq_utils.h into zmq.h, and deprecate
zmq_utils.h. Existing apps can continue unchanged. New apps can ignore
zmq_utils.h completely.

The expect_bounce_fail () helper assumed that messages could always
be sent. However in some cases zmq_send() blocks, due to there not
being any outgoing pipe. This changed in 77f5f7, where previously
there would be a pipe that kept trying to reconnect forever.

Solution: use a send timeout and check for EAGAIN if sending failed.

will not block too long if they go wrong.

failures don't block.

This reverts commit 2a84d259.

Broke regression test on test_hwm.cpp.

These changes cause an assertion in lb_sendpipe() when executing the test_security_plain testcase.

Specifically:

* zmq_event_t should not be used internally in libzmq, it was
  meant to be an outward facing structure.

* In 4.x, zmq_event_t does not correspond to monitor events, so
  I removed the structure entirely.

* man page for zmq_socket_monitor is incomplete and the example
  code was particularly nasty.

* test_monitor.cpp needed rewriting, it was not clean.

* failed on systems where process could not allocate 1024 sockets by default
* include path for platform.hpp was wrong; fixed it

- used msleep (10) in most places instead of zmq_sleep (1)
- may cause failures on slower machines
- to change, modify SETTLE_TIME in testutil.h
- tested down to 1 msec on fast boxes

This reverts commit 015d9564.