Add new port net/cppzmq - C++ bindings for 0MQ

As of ZeroMQ 3.2.0 zmq.hpp has been split into a separate project under
https://github.com/zeromq/cppzmq/releases
https://zeromq.jira.com/browse/LIBZMQ-359

So, FreeBSD's net/libzmq2 does provide zmq.hpp, while net/libzmq3 and
net/libzmq4 do not and this new port net/cppzmq is supplementary to them.

net/Makefile

@@ -84,6 +84,7 @@
     SUBDIR += corkscrew
     SUBDIR += corosync
     SUBDIR += courier-authlib-ldap
+    SUBDIR += cppzmq
     SUBDIR += crtmpserver
     SUBDIR += cryptcat
     SUBDIR += csocks

net/cppzmq/Makefile

@@ -0,0 +1,39 @@
+# Created by: Vasil Dimov <vd@FreeBSD.org>
+# $FreeBSD$
+
+PORTNAME=	cppzmq
+PORTVERSION=	4.2.2
+CATEGORIES=	net
+
+MAINTAINER=	vd@FreeBSD.org
+COMMENT=	C++ bindings for 0MQ
+
+LICENSE=	MIT
+
+LIB_DEPENDS=	libzmq.so:net/libzmq4
+
+USES=		cmake pkgconfig
+CMAKE_ARGS=	--no-warn-unused-cli -Wno-dev
+
+# cppzmq is included in libzmq2
+CONFLICTS=	libzmq2
+
+USE_GITHUB=	yes
+GH_ACCOUNT=	zeromq
+GH_TAGNAME=	v${PORTVERSION}
+
+PLIST_FILES=	\
+	include/zmq.hpp \
+	include/zmq_addon.hpp \
+	share/cmake/Modules/cppzmqConfig.cmake \
+	share/cmake/Modules/cppzmqConfigVersion.cmake \
+	share/cmake/Modules/cppzmqTargets.cmake \
+	share/cmake/Modules/libzmqPkgConfigFallback.cmake
+
+post-patch:
+	${SED} -i '.orig' \
+		-e 's|find_package(ZeroMQ)|find_package(ZeroMQ QUIET)|' \
+		-e 's|share/cmake/$${PROJECT_NAME}|share/cmake/Modules|' \
+		${WRKSRC}/CMakeLists.txt
+
+.include <bsd.port.mk>

net/cppzmq/distinfo

@@ -0,0 +1,3 @@
+TIMESTAMP = 1507013255
+SHA256 (zeromq-cppzmq-4.2.2-v4.2.2_GH0.tar.gz) = 3ef50070ac5877c06c6bb25091028465020e181bbfd08f110294ed6bc419737d
+SIZE (zeromq-cppzmq-4.2.2-v4.2.2_GH0.tar.gz) = 10614

net/cppzmq/pkg-descr

@@ -0,0 +1,3 @@
+C++ bindings for 0MQ
+
+WWW: https://github.com/zeromq/cppzmq