Add explicit license information

The "same license as notmuch" text was probably fine when the file was
contained within the notmuch source repository, but here, externally,
we should be explicit.

diff --git a/notmuch-to-html b/notmuch-to-html
index c3de6969f2cfbd0674f8efa81f587a00cdb7bd2d..f0146f8ea0c6137d15458609603be10635805fba 100755 (executable)
--- a/notmuch-to-html
+++ b/notmuch-to-html
@@ -1,10 +1,23 @@
 #!/usr/bin/python
 #
 # Copyright (c) 2011-2012 David Bremner <david@tethera.net>
-# License: Same as notmuch
+#
 # dependencies
 #       - python 2.6 for json
 #       - argparse; either python 2.7, or install separately
+#
+# 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
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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/ .
 
 from __future__ import print_function
 from __future__ import unicode_literals