[cairo] directFB backend

[何文]

hi：
	I want to use directFB and GTK in my arm board .but when i compile cairo，I get a warning:

--- The directfb surface backend feature is still under active development
--- and is included in this release only as a preview. It does NOT fully work
--- yet and incompatible changes may yet be made to directfb surface backend
--- specific API.

my configue options are these:
./configure --host=arm-linux --build=i686-pc-linux --target=directfb
--prefix=$PREFIX --enable-shared --enable-directfb --enable-freetype --enable-pdf --enable-xlib --
enable-ps --enable-png --disable-win32 --without-x --enable-svg enable-xlib-xrender LDFLAGS="-L$PR
EFIX/lib" CFLAGS="-I$PREFIX/include" --disable-static

I think this warning will make my gtk faulty to work.could you tell me how to eliminate this warning?thanks.