We don't need to look in the library's install dir for dependencies;
 They are all system libraries that should be in other path lists anyhow.

 Fixes Bugzilla #499.

--HG--
branch : SDL-1.2
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/branches/SDL-1.2%403934