Revert "Switch libraries to using new tags."

sdk/lib/io/http.dart

 // Copyright (c) 2012, 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.
 
-part of dart_io;
-
 /**
  * HTTP status codes.
  */
 abstract class HttpStatus {
   static const int CONTINUE = 100;
   static const int SWITCHING_PROTOCOLS = 101;
   static const int OK = 200;
   static const int CREATED = 201;
   static const int ACCEPTED = 202;
   static const int NON_AUTHORITATIVE_INFORMATION = 203;
@@ skipping 1091 matching lines @@
 class RedirectLimitExceededException extends RedirectException {
   const RedirectLimitExceededException(List<RedirectInfo> redirects)
       : super("Redirect limit exceeded", redirects);
 }
 
 
 class RedirectLoopException extends RedirectException {
   const RedirectLoopException(List<RedirectInfo> redirects)
       : super("Redirect loop detected", redirects);
 }