Implement git cl lint.

tests/git_cl_test.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Unit tests for git_cl.py."""
 
 import os
 import StringIO
 import stat
@@ skipping 656 matching lines @@
            'gerrit.chromium.org'],), ''),
         ((['git', 'config', '--unset-all', 'rietveld.cc'],), ''),
         ((['git', 'config', '--unset-all',
            'rietveld.private'],), ''),
         ((['git', 'config', '--unset-all',
            'rietveld.tree-status-url'],), ''),
         ((['git', 'config', '--unset-all',
            'rietveld.viewvc-url'],), ''),
         ((['git', 'config', '--unset-all',
            'rietveld.bug-prefix'],), ''),
+        ((['git', 'config', '--unset-all',
+           'rietveld.cpplint-regex'],), ''),
+        ((['git', 'config', '--unset-all',
+           'rietveld.cpplint-ignore-regex'],), ''),
         ((['git', 'config', 'gerrit.host',
            'gerrit.chromium.org'],), ''),
         # DownloadHooks(False)
         ((['git', 'config', 'gerrit.host'],),
          'gerrit.chromium.org'),
         ((['git', 'rev-parse', '--show-cdup'],), ''),
         ((commit_msg_path, os.X_OK,), False),
         (('https://gerrit-review.googlesource.com/tools/hooks/commit-msg',
           commit_msg_path,), ''),
         ((commit_msg_path,), True),
@@ skipping 46 matching lines @@
       obj = git_cl.ChangeDescription(orig)
       obj.update_reviewers(reviewers)
       actual.append(obj.description)
     self.assertEqual(expected, actual)
 
 
 if __name__ == '__main__':
   git_cl.logging.basicConfig(
       level=git_cl.logging.DEBUG if '-v' in sys.argv else git_cl.logging.ERROR)
   unittest.main()