clutter needs newer MesaLib headers

["Jeremy C. Reed" <reed%reedmedia.net@localhost>]

Okay if I commit this patch?

The clutter build failed because GLX_FRONT_LEFT_EXT and 
GLX_BIND_TO_TEXTURE_RGBA_EXT were not defined. (I had MesaLib-6.4.2nb3 
installed.)

diff -u -r1.1.1.1 options.mk
--- graphics/clutter/options.mk 14 Dec 2008 10:57:18 -0000      1.1.1.1
+++ graphics/clutter/options.mk 11 Apr 2009 16:27:08 -0000
@@ -14,6 +14,7 @@
 CONFIGURE_ARGS+=       --with-x
 CONFIGURE_ARGS+=       --with-flavour=glx
 CONFIGURE_ARGS+=       --with-imagebackend=gdk-pixbuf
+BUILDLINK_API_DEPENDS.MesaLib+= MesaLib>=7.0
 .include "../../graphics/MesaLib/buildlink3.mk"
 .include "../../x11/libX11/buildlink3.mk"
 .include "../../x11/libXdamage/buildlink3.mk"