Ported from libxs revision 123c0f5387ecef287dd11f4dc790fb76ee1c0f67

    Handle insufficient resources on accept() decently

    If accept() call fails due to insuffient OS resources
    the new connection is rejected.

Make socket IO more robust

See also https://zeromq.jira.com/browse/LIBZMQ-433

Forward-port fix for LIBZMQ-211

Update MSVC2008 project after recent changes; fix compilation errors

REP socket demands at least an empty address stack. The server asserted on (msg_->flags () & msg_t::more) in rep.cpp:75 when receiving a malformed request without empty part.

This patch makes a REP socket to discard and silently ignore such malformed requests.

Update MSVC2010 project after recent renames and additions

Visual Studio 2008 compiler defines min/max as macros in its <algorithm> even if <windows.h> is not included at all. This patch defines NOMINMAX to remove these macros and fix compilation on Visual Studio 2008.

This patch fixes the two headers added recently to include our own "stdint.hpp" instead of system <stdint.h> because the latter is not available in Visual Studio versions prior to 2010.

This patch updates MSVC2008 project after device was renamed to proxy and new files were added (tcp.cpp, v1_encoder.cpp and v1_decoder.cpp).

Use <stdint.h> shipped with Visual Studio 2010 and later

This patch updates MSVC2010 project after device was renamed to proxy and new files were added (v1_encoder.cpp and v1_decoder.cpp).

Visual Studio didn’t have <stdint.h> until 2010, therefore we had a bunch of typedefs for int8_t, int16_t and the likes in "stdint.hpp". This patch limits these typedefs to Visual Studio versions older than 2010 and uses compiler-shipped <stdint.h> on 2010 and newer.

Init msg in pgm_receiver drop subs

Fixes reported issue with PGM receiver on 32bit Suse where asserts
were hit due to the msg flags not being zeroed.

Fix monitor

zmq_msg_t will now typedef a named struct.

This change allows forward declaration of struct zmq_msg_t.

Significantly reworked the monitoring infrastructure with a more granular per socket API and to play well with monitoring endpoints in application threads

Update doc/zmq_msg_get.txt

Add pthread.h include to test_connect_delay.cpp

This test case uses pthreads, but doesn't include the header.

Replaced device concept with proxy concept

* zmq_device is now a wrapper that calls zmq_proxy
* zmq_proxy adds capture socket

Add "#undef NDEBUG" to all tests.

This change makes sure that even if the tests are built in a
"release" configuration (with optimizations and NDEBUG turned on),
the assertions won't get compiled out of the tests themselves.

The C standard guarantees that the most recent inclusion of
<assert.h> is the one that counts, so it's important that the
"#undef NDEBUG/#include <assert.h>" come as the last thing in
the block of header files.

"testutil.hpp" includes <assert.h>, so I've left <assert.h> out
of any test that #includes "testutil.hpp", just for the sake of
brevity.

New message encoder/decoder + code simplification

This is supposed to become part of the ZMTP/1.1.

The main differences from the ZMTP/1.0 framing protocol are:
- flags field comes first, followed by the length field
- long messages are signaled using a flag rather then 0xff escape
- length field does not include the flags field, 0 is a valid value

Fix some PGM refactor breakages

Hopefully fixed LIBZMQ-427 - there was a slight typo in the init_address
refactor. The encoder refactoring had also broken pgm_sender and
receiver, but just required updating to use the new functions.

Code cleanup