Rename type zmq_monitor_fn -> zmq_monitor for a more natural callback definition API (zmq_monitor type, monitor.function callback)

Change zmq_monitor_fn type to cast between pointer-to-object and pointer-to-function in a more standards compliant way

Assign arbitrary number of filters that will be applied for each new TCP transport
connection on a listening socket.
If no filters applied, then TCP transport allows connections from any ip.
If at least one filter is applied then new connection source ip should be matched.
To clear all filters call zmq_setsockopt(socket, ZMQ_TCP_ACCEPT_FILTER, NULL, 0).
Filter is a null-terminated string with ipv6 or ipv4 CIDR.

For example:
localhost
127.0.0.1
mail.ru/24
::1
::1/128
3ffe:1::
3ffe:1::/56

Returns -1 if the filter couldn't be assigned(format error or ipv6 filter with ZMQ_IPV4ONLY set)

P.S.
The only thing that worries me is that I had to re-enable 'default assign by reference constructor/operator'
for 'tcp_address_t' (and for my inherited class tcp_address_mask_t) to store it in std::vector in 'options_t'...

currently not fully cross-platform
work on linux
possibly work in *bsd
and could be enhanced to work on windows

* Return integer property
* Fixed up man pages, which were inaccurate
* Fixed test case

* Implemented new ctx API (_new, _destroy, _get, _set)
* Removed 'typesafe' macros from zmq.h
* Added support for MAX_SOCKETS (was tied into change for #337)
* Created new man pages

 - reverted commit 941be8d2.
 - fixed zmq_device implementation for latest socket_base class
 - added back zmq_device.3 man page

* Added two new files: errno.hpp and errno.cpp. They are required to use errno functionality on WM.
* zmq.cpp, msg.h: removed inclusion of errno.h because it is included in zmq.h that is also included by .cpp.
* windows.hpp: process.h is included only for desktop builds.
* thread.cpp: on CE CreateThread is used instead of __beginthreadex
* socket_base.cpp, clock.cpp: on CE include cmnintrin.h instead on intrin.h
* signaler.cpp: on Windows should use special macro around event name (for unicode builds)
* err.hpp: make it include errno.hpp (my file) instead on errno.h when building for CE
* err.cpp: use FormatMessage when building for CE (because CE does not have ANSI API functions)
* zmq.h: do not include errno.h whe building for CE
* libzmq.vcproj: add tro new files

* Added zmq_msg_poke for orthogonality
* Added zmq_msg_more for simplicity
* Fixed up man pages and test program

We have to use an incomplete type in the interface.
The definition of iovec is only in the implementation.
This appears to following existing practice in 0MQ.
It seems a bit flakey that zmq.h is not included in zmq.cpp,
which is normal practice to ensure the implementation matches
the specified interface. YMMV. I follow 0MQ style.

Also move iovec definition from implementation to interface.
Not clear to me at present if an incomplete type should
be used to avoid gratuitously including <sys/uio.h> in
the interface. The interface can't be used with this include.

We use a distinct context initialisation function to specify
all sockets derived therefrom will be thread safe.

However the inheritance is done exclusively in the C interface.
This is not really correct, but it is chosen to minimise
interference with the existing C++ code, including any
construct or other calls within the C++ code base.
Semantically the C++ code should be unchanged,
physically some data structures and extra methods are
provided by they're only used from the C binding.

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

The new function allows to retrieve options (flags)
from zmq_msg_t.
Signed-off-by: Chuck Remes <cremes@mac.com>
Renamed from zmq_msg_flags to zmq_getmsgopt
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

This version downgrade is done because of the previous refatoring.
It removed all the new features and reintroduced some of the old
ones (identities). Thus, it made trunk much closer to existing 3.0
branch than it used to be.
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

This error code was used only by new-style ROUTER socket
which is not a part of the codebase.
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>