fixes for removing update keys

tool/sexp.py

@@ -2,6 +2,27 @@
 #
 # See: http://people.csail.mit.edu/rivest/sexp.html
 #
+"""
+sexp.py - a library for SEXP
+
+Copyright (C) 2013 Free Software Initiative of Japan
+Author: NIIBE Yutaka <gniibe@fsij.org>
+
+This file is a part of Gnuk, a GnuPG USB Token implementation.
+
+Gnuk 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.
+
+Gnuk 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/>.
+"""
 
 import re