Add support for Solaris 10 ACLs. Also, ACLs are Gnulib, not Autoconf.

Add support for Solaris 10 ACLs.  Also, ACLs are Gnulib, not Autoconf.

* modules/acl (configure.ac): Rename AC_FUNC_ACL to gl_FUNC_ACL.
* m4/acl.m4 (gl_FUNC_ACL): Renamed from AC_FUNC_ACL.  On Solaris,
put -lsec in even for programs other than 'ls'.  This fixes a problem
for gettext reported by Bruno Haible in
<http://lists.gnu.org/archive/html/bug-gnulib/2007-12/msg00007.html>.
* lib/acl.c (copy_acl, qset_acl) [USE_ACL && defined ACL_NO_TRIVIAL]:
Add support for Solaris 10.  This isn't efficient, but should get the
job done for now.