Revert "Switch libraries to using new tags."

sdk/lib/io/http_utils.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;
-
 class _HttpUtils {
   static String decodeUrlEncodedString(String urlEncoded) {
     // First check the string for any encoding.
     int index = 0;
     bool encoded = false;
     while (!encoded && index < urlEncoded.length) {
       encoded = urlEncoded[index] == "+" || urlEncoded[index] == "%";
       index++;
     }
     if (!encoded) return urlEncoded;
@@ skipping 333 matching lines @@
     int hour = toInt(timeList[0]);
     int minute = toInt(timeList[1]);
     int second = toInt(timeList[2]);
     if (hour > 23) error();
     if (minute > 59) error();
     if (second > 59) error();
 
     return new Date.utc(year, month, dayOfMonth, hour, minute, second, 0);
   }
 }