Java2D's shared libraries should hide mediaLib symbols to avoid name conflict

In JDK 1.3.1 for Solaris, from the results of nm(1) on libmlib_image.so and
libmlib_image_v.so in jre/lib/sparc, I can see that symbols in form of
"mlib_Image..." are being exported as globals. This might cause conflicts
between these .so libraries and other versions of mediaLib libraries.

In JDK 1.4.0 beta, the .so files have been stripped so that nm(1) can
not tell what symbols are being exported. But I think the problem still
exists.