Pass ${X11BASE}/include when building tkagg extension.

Fixes build with newer freetype.

graphics/py-matplotlib/Makefile

@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.47 2014/01/04 21:21:55 jasper Exp $
+# $OpenBSD: Makefile,v 1.48 2014/01/10 19:05:07 landry Exp $
 
 COMMENT=	Python charting and plotting API
 
@@ -41,6 +41,7 @@ MAKE_ENV+=	EXTRA_INCLUDES="${WRKSRC} ${MODTCL_INCDIR} ${MODTK_INCDIR}" \
 
 pre-configure:
 	@find ${WRKSRC}/examples -name \*.py | xargs ${MODPY_BIN_ADJ}
+	${SUBST_CMD} ${WRKSRC}/setupext.py
 
 post-install:
 	${INSTALL_DATA_DIR} ${PREFIX}/share/examples/py-matplotlib

graphics/py-matplotlib/patches/patch-setupext_py

@@ -0,0 +1,11 @@
+$OpenBSD: patch-setupext_py,v 1.14 2014/01/10 19:05:07 landry Exp $
+--- setupext.py.orig	Fri Jan 10 19:53:17 2014
++++ setupext.py	Fri Jan 10 19:56:08 2014
+@@ -1167,6 +1167,7 @@ def build_tkagg(ext_modules, packages):
+                        define_macros=defines
+                        )
+ 
++    module.include_dirs.extend(['${X11BASE}/include'])
+     add_tk_flags(module) # do this first
+     add_agg_flags(module)
+     add_ft2font_flags(module)