Fix issue #971

Fix issue #969

Fixed issue #967

Fixes #967

Update VS build configurations.

Incorporate libsodium option and linkage, generalize, update packaging.

Update NuGet packaging metadata.

Rationalize and update Visual Studio projects and packaging.

- this failing test was confusing users
- ZMTP v3.0 now does not define resources at all
- resources, along with other unimplemented aspects moved to
  RFC 37 ZMTP v3.1

Update and add executable projects to VS2013 solution.

Resolve issue #939

This bug is caused by fq which can terminate pipe before sending all
frames of a message first. So sometimes two messages were mixed and this
confused ZAP handler.

This patch just modifies one pipe parameter so that socket consumes all
messages before dropping the pipe.

sockets created by accept are leaked to child processes (ticket #956)

Organize Visual Studio solutions and integrate NuGet packaging.

Make a NuGet package

Allow iov_base as char * on Solaris 8/9/10.

Include zmq.h after platform.hpp

On Solaris 8, 9, 10/SPARC, iov_base is of type caddr_t which is char *. The Sun C++ compiler errors with "Cannot assign void* to char*". Using a static case to override this. On Solaris 11, HP-UX, AIX, and RHEL, iov_base is void * so no issues there. This seems a rather hackish solution so open to something better.