Install symlinks for shared library

Hello,

Here's a patch I'm using to install the "*.so" and "*.so.$(API_MAJOR)"
symlinks for the shared library via the build system. The patch can be
viewed and downloaded from [1]. I took care of ensuring this change
would be portable across many different platforms.

1. http://anonscm.debian.org/gitweb/?p=pkg-multimedia/xvidcore.git;a=blob;f=debian/patches/add-soname-links.patch

-- 
Regards,
Andres Mejia