Merge branch 'master' of https://github.com/zeromq/libzmq
Merge pull request #1121 from twhittock/master

vs2012: Add missing socks files
Windows: if WSA error number is held, use directly.
It must be done this way, as WSAGetLastError returns 0 in these circumstances
Merge pull request #1122 from twhittock/win-errhandle

Windows: if WSA error number is held, use directly.
Resolve issue #949
Merge pull request #1123 from hurtonm/master

Resolve issue #949
Merge branch 'master' of https://github.com/zeromq/libzmq
Add test for unbinding inproc socket.
Merge pull request #1124 from ricnewton/master

Add test for unbinding inproc socket.
Code cleanup
Merge pull request #1125 from hurtonm/master

Code cleanup
Ensure EOL is present at end of utils file.

MacOS/Clang complain due to presence of -Wnewline-eof in CZMQ.
Merge pull request #1127 from twhittock/utils-eol

Ensure EOL is present at end of utils file.
Add Docker support
Merge pull request #1130 from trevorbernard/master

Add Docker support
Added ZMQ_SHARED message option to zmq_msg_get()
Merge pull request #1131 from rodgert/master

Added ZMQ_SHARED message option to zmq_msg_get()
Added test and doc section for ZMQ_SHARED message flag
Merge pull request #1132 from rodgert/master

Added test and doc section for ZMQ_SHARED message flag
builds/zos/* portability files to z/OS UNIX

builds/zos includes:
    README.md: Overview of z/OS UNIX System Services port (Markdown)
    makelibzmq: Compile src/*.cpp and make libzmq.a
    maketests:  Compile tests/*.cpp and make test_* executables
    runtests:   Run tests/test_* executables and report results
    makeclean:  Remove built files
    zc++: /bin/c++ wrapper supplying required build arguments
    cxxall: run zc++ for all *.cpp files in directory

    platform.hpp: pre-generated (and edited) src/platform.hpp for z/OS
    test_fork.cpp: updated tests/test_fork.cpp that completes on z/OS