Create new port graphics/py3-pygraphviz:

- This is a variant of graphics/py-pygraphviz for Python 3.x.
  A separate port is needed until the ports tree gets VARIANTS support.
  The science/gramps port will soon be updated to a version which only
  supports python3, and it depends on py-pygraphviz with python3.
  To allow people to only use packages directly (and not ports),
  the package building infrastructure needs to build 2 packages:
  py-pygraphviz with python2 and py-pygraphviz with python3.
  Since the ports tree doesn't yet have VARIANTS support, this is not
  yet possible without making a separate py3-pygraphviz port.
- Ensure graphics/py-pygraphviz does not clobber variables in slave port
- While here, add LICENSE and LICENSE_FILE details to graphics/py-pygraphviz

PR:		207039
Approved by:	mat (mentor)
Differential Revision:	https://reviews.freebsd.org/D6281

graphics/Makefile

@@ -882,6 +882,7 @@
     SUBDIR += py-webcolors
     SUBDIR += py3-cairo
     SUBDIR += py3-pillow
+    SUBDIR += py3-pygraphviz
     SUBDIR += pygts
     SUBDIR += pymorph
     SUBDIR += pysvg

graphics/py-pygraphviz/Makefile

@@ -10,11 +10,13 @@ PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 MAINTAINER=	python@FreeBSD.org
 COMMENT=	Python interface to GraphViz agraph
 
+LICENSE=	BSD3CLAUSE
+LICENSE_FILE=	${WRKSRC}/LICENSE
 
 LIB_DEPENDS=	libcgraph.so:graphics/graphviz
-TEST_DEPENDS=	${PYTHON_PKGNAMEPREFIX}nose>=0.10.1:devel/py-nose
+TEST_DEPENDS?=	${PYTHON_PKGNAMEPREFIX}nose>=0.10.1:devel/py-nose
 
-USES=		pkgconfig python
+USES?=		pkgconfig python
 USE_PYTHON=	autoplist concurrent distutils
 
 PYDISTUTILS_BUILD_TARGET=	build build_ext

graphics/py3-pygraphviz/Makefile

@@ -0,0 +1,10 @@
+# Created by: Ben Woods <woodsb02@FreeBSD.org>
+# $FreeBSD$
+
+MASTERDIR=	${.CURDIR}/../py-pygraphviz
+
+TEST_DEPENDS=	${PYTHON_PKGNAMEPREFIX}nose>=0.10.1:devel/py3-nose
+
+USES=		pkgconfig python:3.4+
+
+.include "${MASTERDIR}/Makefile"