maint: update copyrights for 2013 and as per current GNU standards

gnulib.modules

@@ -1,6 +1,23 @@
 # List of gnulib modules needed for GNU tar.
 # A module name per line. Empty lines and comments are ignored.
 
+# Copyright 2005-2010, 2012-2013 Free Software Foundation, Inc.
+
+# This file is part of GNU tar.
+
+# GNU tar is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+
+# GNU tar is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 acl
 alloca
 argmatch