For exchanging tokens.

E.g., both client and server need to produce and process GSSAPI tokens.

Update file tools versioning in VS projects.

Conflicts:
	builds/msvc/vs2010/inproc_lat/inproc_lat.props
	builds/msvc/vs2010/inproc_thr/inproc_thr.props
	builds/msvc/vs2010/libsodium.import.props
	builds/msvc/vs2010/libzmq.import.props
	builds/msvc/vs2010/libzmq/libzmq.props
	builds/msvc/vs2010/local_lat/local_lat.props
	builds/msvc/vs2010/local_thr/local_thr.props
	builds/msvc/vs2010/properties/Common.props
	builds/msvc/vs2010/properties/Console.props
	builds/msvc/vs2010/properties/ConsoleDebugDynamic.props
	builds/msvc/vs2010/properties/ConsoleDebugLinkTimeCodeGeneration.props
	builds/msvc/vs2010/properties/ConsoleDebugStatic.props
	builds/msvc/vs2010/properties/ConsoleReleaseDynamic.props
	builds/msvc/vs2010/properties/ConsoleReleaseLinkTimeCodeGeneration.props
	builds/msvc/vs2010/properties/ConsoleReleaseStatic.props
	builds/msvc/vs2010/properties/Debug.props
	builds/msvc/vs2010/properties/Dynamic.props
	builds/msvc/vs2010/properties/DynamicDebug.props
	builds/msvc/vs2010/properties/DynamicRelease.props
	builds/msvc/vs2010/properties/LinkTimeCodeGeneration.props
	builds/msvc/vs2010/properties/Release.props
	builds/msvc/vs2010/properties/Static.props
	builds/msvc/vs2010/properties/StaticDebug.props
	builds/msvc/vs2010/properties/StaticDebugLinkTimeCodeGeneration.props
	builds/msvc/vs2010/properties/StaticLinkTimeCodeGeneration.props
	builds/msvc/vs2010/properties/StaticRelease.props
	builds/msvc/vs2010/properties/StaticReleaseLinkTimeCodeGeneration.props
	builds/msvc/vs2010/properties/Win32.props
	builds/msvc/vs2010/properties/x64.props
	builds/msvc/vs2010/remote_lat/remote_lat.props
	builds/msvc/vs2010/remote_thr/remote_thr.props

Fixed mingw poll detection

Change ToolsVersion to 4.0 for VS2010

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)