Add new InternetAddress class with a static lookup function (including IPv6 results).

tests/standalone/io/secure_socket_test.dart

 // Copyright (c) 2013, 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 "package:expect/expect.dart";
 import "dart:async";
 import "dart:io";
 
 Future<HttpServer> startServer() {
   return HttpServer.bindSecure(
-      "127.0.0.1",
+      "localhost",
       0,
       backlog: 5,
       certificateName: 'localhost_cert').then((server) {
     server.listen((HttpRequest request) {
       request.listen(
         (_) { },
         onDone: () {
           request.response.contentLength = 100;
           for (int i = 0; i < 10; i++) {
             request.response.add([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
@@ skipping 31 matching lines @@
         },
         onError: (e) {
           String msg = "Unexpected error $e";
           var trace = getAttachedStackTrace(e);
           if (trace != null) msg += "\nStackTrace: $trace";
           Expect.fail(msg);
         });
     });
   });
 }