Move to using cherrypy.

This moves our devserver from using web to use cherrypy.
Cherrypy is more robust and provides byte range continuations than web.py.

Change-Id: I674f213a6c8c5de68e9ba78d3e97b682c016803f

BUG=7395
TEST=Ran with latest, forced, and archive_dir.  Tests for factory are ongoing.

Review URL: http://codereview.chromium.org/3708004
diff --git a/buildutil.py b/buildutil.py
index 3700ef3..2447b2c 100644
--- a/buildutil.py
+++ b/buildutil.py
@@ -1,12 +1,7 @@
-# Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
+# Copyright (c) 2009-2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import os
-import web
-from datetime import datetime
-import time 
-
 class BuildObject(object):
   """
     Common base class that defines key paths in the source tree.