maint: update to latest gnulib

'make syntax-check' warned that gnulib's copyright is now out of date.

* .gnulib: Update to latest, for copyright year bump.
* gnulib/local/m4/ssize_t.m4.diff: Regenerate.
* bootstrap: Synchronize from upstream.

.gnulib @ 964bbc2d

-Subproject commit d245e6ddd6ab2624d0d83acd8f111454f984f50f
+Subproject commit 964bbc2d419584e93fe629ddbc40595612f62083

bootstrap

 #! /bin/sh
 # Print a version string.
-scriptversion=2012-07-19.14; # UTC
+scriptversion=2012-12-28.10; # UTC
 
 # Bootstrap this package from checked-out sources.
 
-# Copyright (C) 2003-2012 Free Software Foundation, Inc.
+# Copyright (C) 2003-2013 Free Software Foundation, Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -889,20 +889,21 @@ find "$m4_base" "$source_base" \
   -depth \( -name '*.m4' -o -name '*.[ch]' \) \
   -type l -xtype l -delete > /dev/null 2>&1
 
+# Invoke autoreconf with --force --install to ensure upgrades of tools
+# such as ylwrap.
+AUTORECONFFLAGS="--verbose --install --force -I $m4_base $ACLOCAL_FLAGS"
+
 # Some systems (RHEL 5) are using ancient autotools, for which the
 # --no-recursive option had not been invented.  Detect that lack and
 # omit the option when it's not supported.  FIXME in 2017: remove this
 # hack when RHEL 5 autotools are updated, or when they become irrelevant.
-no_recursive=
 case $($AUTORECONF --help) in
-  *--no-recursive*) no_recursive=--no-recursive;;
+  *--no-recursive*) AUTORECONFFLAGS="$AUTORECONFFLAGS --no-recursive";;
 esac
 
 # Tell autoreconf not to invoke autopoint or libtoolize; they were run above.
-echo "running: AUTOPOINT=true LIBTOOLIZE=true " \
-    "$AUTORECONF --verbose --install $no_recursive -I $m4_base $ACLOCAL_FLAGS"
-AUTOPOINT=true LIBTOOLIZE=true \
-    $AUTORECONF --verbose --install $no_recursive -I $m4_base $ACLOCAL_FLAGS \
+echo "running: AUTOPOINT=true LIBTOOLIZE=true $AUTORECONF $AUTORECONFFLAGS"
+AUTOPOINT=true LIBTOOLIZE=true $AUTORECONF $AUTORECONFFLAGS \
   || die "autoreconf failed"
 
 # Get some extra files from gnulib, overriding existing files.

gnulib/local/m4/ssize_t.m4.diff

@@ -5,7 +5,7 @@ index 209d64c..5ea72a1 100644
 @@ -1,4 +1,4 @@
 -# ssize_t.m4 serial 5 (gettext-0.18.2)
 +# ssize_t.m4 serial 6 (gettext-0.18.2)
- dnl Copyright (C) 2001-2003, 2006, 2010-2012 Free Software Foundation, Inc.
+ dnl Copyright (C) 2001-2003, 2006, 2010-2013 Free Software Foundation, Inc.
  dnl This file is free software; the Free Software Foundation
  dnl gives unlimited permission to copy and/or distribute it,
 @@ -17,7 +17,21 @@ AC_DEFUN([gt_TYPE_SSIZE_T],