Merge pull request #137 from TTimo/master

Fix MSVC 2012
Added NULL pointer check to s_get_interface
Merge pull request #138 from jpulver/master

Fixed crash (NULL pointer) in zbeacon/s_get_interface
Adjust the library paths for x64 builds to look in libzmq\lib\x64 first

Fallback on x64 is still libzmq\lib
Merge pull request #139 from vortechs2000/cleanup_dll_paths

Adjust the library paths for x64 builds to look in libzmq\lib\x64 first
Make sure LIBCZMQ_EXPORTS is defined for all DLL configurations

And make sure LIBZMQ_EXPORTS and DLL_EXPORT are not defined for static
configurations.

This allows the ReleaseDLL configuration to build against a release zeromq
library.
Merge pull request #142 from vortechs2000/more_dll_cleanup

Make sure LIBCZMQ_EXPORTS is defined for all DLL configurations
Enable callbacks on zframe_destroy
Merge pull request #143 from raggi/zframe_freefn

Enable callbacks on zframe_destroy
Fixed issue #144
Updated version for 1.4.0
Fixed some errors in NEWS
Merge pull request #145 from hintjens/master

Fixed #144 and other small issues
Removed unneeded zmq_msg_close calls
Merge pull request #146 from hintjens/master

The code was doing a couple of redundant calls, removed those
update man pages
Merge pull request #147 from stephen-wolf/master

update generated man pages
move czmq API man pages to section 3
Merge pull request #149 from stephen-wolf/master

move czmq API man pages to section 3
Added configure check for libsodium