Add copyright information to .py files

This change adds explicit copyright information too python
files files.  The copyright year used in each case is the
date of the first git commit of each file.

The goal is to allow jsoncpp to be integrated into the
chromium source tree which requires license information in
each source file.

fixes #234
diff --git a/devtools/antglob.py b/devtools/antglob.py
index afd4c48..c272f66 100644
--- a/devtools/antglob.py
+++ b/devtools/antglob.py
@@ -1,6 +1,9 @@
 #!/usr/bin/env python
 # encoding: utf-8
-# Baptiste Lepilleur, 2009
+# Copyright 2009 Baptiste Lepilleur
+# Distributed under MIT license, or public domain if desired and
+# recognized in your jurisdiction.
+# See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
 
 from __future__ import print_function
 from dircache import listdir