Remove ldconfig_paths_aout, it is no longer used.

Remove ldconfig_paths_aout, it is no longer used.
Add /usr/pkg/lib to the default ldconfig_paths and remove /usr/X11R6/lib.
The path is now: /usr/lib/compat /usr/pkg/lib /usr/pkg/xorg/lib /usr/local/lib

pkgsrc packages use rpaths - absolute paths, and do not need ldd library
search paths.  However, we do want these libraries to be easily accessible
to manually compiled programs and until GCC starts using rpaths by default,
maintaining a default list is a good idea.

Submitted-by:	Hasso Tepper <hasso@estpak.ee>