contribs: updated binary package for OS X

Includes ffmpeg r19836, all other contents remained unchanged, so libtheora is not up-to-date

extras/contrib/Makefile

@@ -47,11 +47,8 @@ src: using-src
 
 ifdef HAVE_DARWIN_OS
 
-ifdef HAVE_DARWIN_OS_ON_INTEL
-CONTRIBREV=19
-else
-CONTRIBREV=18
-endif
+CONTRIBREV=20
+
 contrib-macosx-$(ARCH)-$(CONTRIBREV).tar.bz2:
 	$(WGET) http://downloads.videolan.org/pub/videolan/testing/contrib/$@