Merge pull request #952 from evoskuil/master

Organize Visual Studio solutions and integrate NuGet packaging.
sockets created by accept are leaked to child processes (ticket #956)
Merge pull request #957 from jkryl/master

sockets created by accept are leaked to child processes (ticket #956)
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.
Merge pull request #958 from hurtonm/master

Resolve issue #939
Merge branch 'zeromq/master'