Re-implement support for client redirects.

tests/standalone/io/http_basic_test.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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 import "dart:isolate";
@@ skipping 271 matching lines @@
   });
   testServerMain.start();
 }
 
 void testReasonPhrase() {
   TestServerMain testServerMain = new TestServerMain();
   testServerMain.setServerStartedHandler((int port) {
     HttpClient httpClient = new HttpClient();
     httpClient.get("127.0.0.1", port, "/reasonformoving")
         .then((request) {
-          // request.followRedirects = false;
+          request.followRedirects = false;
           return request.close();
         })
         .then((response) {
           Expect.equals(HttpStatus.MOVED_PERMANENTLY, response.statusCode);
           Expect.equals("Don't come looking here any more",
                         response.reasonPhrase);
           response.listen(
               (data) => Expect.fail("No data expected"),
               onDone: () {
                 httpClient.close();
                 testServerMain.close();
               });
         });
   });
   testServerMain.start();
 }
 
 void main() {
   testStartStop();
   testGET();
   testPOST(true);
   testPOST(false);
   test404();
   testReasonPhrase();
 }