add copyrights on Python2

runtime/Python2/src/antlr4/IntervalSet.py

@@ -1,3 +1,9 @@
+#
+# Copyright (c) 2012 The ANTLR Project Contributors. All rights reserved.
+# Use is of this file is governed by the BSD 3-clause license that
+# can be found in the LICENSE.txt file in the project root.
+#
+
 from io import StringIO
 import unittest
 from antlr4.Token import Token

runtime/Python2/src/antlr4/ListTokenSource.py

@@ -1,3 +1,9 @@
+#
+# Copyright (c) 2012 The ANTLR Project Contributors. All rights reserved.
+# Use is of this file is governed by the BSD 3-clause license that
+# can be found in the LICENSE.txt file in the project root.
+#
+
 #
 # Provides an implementation of {@link TokenSource} as a wrapper around a list
 # of {@link Token} objects.

runtime/Python2/src/antlr4/tree/Chunk.py

@@ -1,3 +1,9 @@
+#
+# Copyright (c) 2012 The ANTLR Project Contributors. All rights reserved.
+# Use is of this file is governed by the BSD 3-clause license that
+# can be found in the LICENSE.txt file in the project root.
+#
+
 class Chunk(object):
 
     def __str__(self):

runtime/Python2/src/antlr4/xpath/XPath.py

@@ -1,3 +1,8 @@
+#
+# Copyright (c) 2012 The ANTLR Project Contributors. All rights reserved.
+# Use is of this file is governed by the BSD 3-clause license that
+# can be found in the LICENSE.txt file in the project root.
+#
 
 #
 # Represent a subset of XPath XML path syntax for use in identifying nodes in