r23689: Squashed commit of the following:

r23689: Squashed commit of the following:

commit 0d4bbd197198a94bf4e29e0ccd175a40a60097f3
Author: Gerald (Jerry) Carter <jerry@samba.org>
Date:   Mon Jul 2 20:08:19 2007 -0500

    Introduce GNU ld linker export-script for hiding non-public symbols
    in shared libraries.

    Based on initial patch from Julien Cristau <jcristau@debian.org>
    and suggestions from James Peach <jpeach@samba.org>.  Currently
    the libsmbsharemodes libraries still exports *.  Signed off on
    my Derrell as well.
(This used to be commit c42cf731b4b259c5c1a874fd1837ca85144f1a58)