Rearrange files

+ move remaining data models into dm/
+ remove tr/tornado, tr/bup, and pynetlinux symlinks.
+ Instead, use sys.path.append("...") in every unit test and runserver.py.
  I know sys.path is ugly. Nonetheless the module problem making tornado code
    think it had a different module path than the rest of the source was
    killing me.
+ Remove tornadi_fix, no longer needed.
+ Revert tornado.httpclient Curl hack, restore it to SimpleHttpClient.
  configure("curl_httpclient") in runserver.py, the way it should be done.
+ fix acs_integration_test, broken by Listen(acs_url_file) change
+ fix api_test, broken by the cwmp:ID. Don't make exact XML comparisons.
diff --git a/tornado/httpclient.py b/tornado/httpclient.py
index b542939..9f45b0a 100644
--- a/tornado/httpclient.py
+++ b/tornado/httpclient.py
@@ -116,8 +116,8 @@
         else:
             if cls is AsyncHTTPClient:
                 if cls._impl_class is None:
-                    from tornado.curl_httpclient import CurlAsyncHTTPClient
-                    AsyncHTTPClient._impl_class = CurlAsyncHTTPClient
+                    from tornado.simple_httpclient import SimpleAsyncHTTPClient
+                    AsyncHTTPClient._impl_class = SimpleAsyncHTTPClient
                 impl = cls._impl_class
             else:
                 impl = cls