Add template comments; update copyright in template file in anticipation of new uses.

lib/dom/scripts/templateloader_test.py

 #!/usr/bin/python
 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 import logging.config
 import unittest
 import templateloader
 
 class TemplateLoaderTestCase(unittest.TestCase):
@@ skipping 26 matching lines @@
         self.fail("'%s' does not contain '%s'" % (e, expected_message))
     if not threw:
       self.fail("missing error, expected '%s'" % expected_message)
 
 
   def test_freevar(self):
     input_text = '''$A
 $B'''
     self._preprocess_test(input_text, {}, input_text)
 
+  def test_comments(self):
+    input_text = '''//$ comment 1
+Hello
+//$ comment 2'''
+    self._preprocess_test(input_text, {}, 'Hello\n')
+
 
   def test_ite1(self):
     input_text = '''
         aaa
         $if A
         bbb
         $else
         ccc
         $endif
         ddd
@@ skipping 59 matching lines @@
     input_text = '''
        $if A
        $else
        '''
     self._preprocess_error_test(input_text, {'A':True}, 'Unterminated')
 
 if __name__ == "__main__":
   logging.config.fileConfig("logging.conf")
   if __name__ == '__main__':
     unittest.main()