actual libffi support!

builds/libraries/vendor/libffi

@@ -12,17 +12,10 @@ echo "Building libffi..."
 
 SOURCE_TARBALL='http://cl.ly/2s1t1u3v0N0I/download/libffi-3.1.tar'
 
-curl -L $SOURCE_TARBALL | tar xz
+curl -L $SOURCE_TARBALL | tar x
 
 cd libffi-3.1
-
-
-sed -e '/^includesdir/ s:$(libdir)/@PACKAGE_NAME@-@PACKAGE_VERSION@/include:$(includedir):' \
-    -i include/Makefile.in &&
-sed -e '/^includedir/ s:${libdir}/@PACKAGE_NAME@-@PACKAGE_VERSION@/include:@includedir@:' \
-    -e 's/^Cflags: -I${includedir}/Cflags:/' \
-    -i libffi.pc.in        &&
-./configure --prefix=/usr --disable-static &&
+./configure --prefix=$OUT_PREFIX --disable-static &&
 make
 make install