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
Fixed some typedef inconsistency
ensure zhash_foreach stops on non-zero return
Merge pull request #150 from avalanche123/5e5d99b607f0ca2ddebad6aa0569884eaf6bf0a1

fix zhash_foreach behavior
add zhash_foreach test
minor cosmetic fix