Make the dartdoc.py script pull the master version of the client rather than dev

pkg/docgen/bin/dartdoc.py

 #!/usr/bin/env python
 #
 # Copyright (c) 2013, 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. 
 
 """ Run this script to generate documentation for a directory and serve
   the results to localhost for viewing in the browser.
 """
 
@@ skipping 36 matching lines @@
   options = parser.parse_args()
   SetPackageRoot(options.pkg_root)
   return options
 
 def main():
   options = GetOptions()
   docgen = [DART, '--checked', '--package-root=' + PACKAGE_ROOT,
     join(DIRECTORY, 'docgen.dart')]
   docgen.extend(options.options.split())
   ExecuteCommand(docgen)
-  ExecuteCommand(['git', 'clone', '-b', 'dev',
+  ExecuteCommand(['git', 'clone', '-b', 'master',
    'git://github.com/dart-lang/dartdoc-viewer.git'])
   ExecuteCommand(['mv', 'docs', 'dartdoc-viewer/client/local'])
   os.chdir('dartdoc-viewer/client/')
   subprocess.call([PUB, 'install'])
   subprocess.call([DART, 'build.dart'])
   subprocess.call([DART2JS, '-o', 'web/out/index.html_bootstrap.dart.js', 
     './web/out/index.html_bootstrap.dart'])
   server = subprocess.Popen(['python', 
     join(abspath(join(dirname(__file__), options.gae_sdk)), 'dev_appserver.py'),
     '..'])
   print("\nPoint your browser to the address of the 'default' server below.")
   raw_input("Press <RETURN> to terminate the server.\n\n")
   server.terminate()
   os.chdir('../..')
   subprocess.call(['rm', '-rf', 'dartdoc-viewer'])
 
 if __name__ == '__main__':
   main()