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

tests/standalone/io/socket_ipv6_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.
-
-import 'dart:io';
-import 'dart:isolate';
-
-void testIPv6toIPv6() {
-  ServerSocket.bind("::0").then((server) {
-    server.listen((socket) {
-      socket.destroy();
-      server.close();
-    });
-    Socket.connect("::1", server.port).then((socket) {
-      socket.destroy();
-    });
-  });
-}
-
-void testIPv4toIPv6() {
-  ServerSocket.bind("::0").then((server) {
-    server.listen((socket) {
-      socket.destroy();
-      server.close();
-    });
-    Socket.connect("127.0.0.1", server.port).then((socket) {
-      socket.destroy();
-    });
-  });
-}
-
-void testIPv6toIPv4() {
-  ServerSocket.bind("127.0.0.1").then((server) {
-    server.listen((socket) {
-      throw "Unexpected socket";
-    });
-    Socket.connect("::1", server.port).catchError((e) {
-      server.close();
-    });
-  });
-}
-
-void testIPv4toIPv4() {
-  ServerSocket.bind("127.0.0.1").then((server) {
-    server.listen((socket) {
-      socket.destroy();
-      server.close();
-    });
-    Socket.connect("127.0.0.1", server.port).then((socket) {
-      socket.destroy();
-    });
-  });
-}
-
-void testIPv6Lookup() {
-  var port = new ReceivePort();
-  InternetAddress.lookup("::0").then((list) {
-    if (list.length < 0) throw "no address";
-    for (var entry in list) {
-      if (entry.type != InternetAddressType.IPv6) {
-        throw "Wrong IP type";
-      }
-    }
-    port.close();
-  });
-}
-
-void testIPv4Lookup() {
-  var port = new ReceivePort();
-  InternetAddress.lookup("127.0.0.1").then((list) {
-    if (list.length < 0) throw "no addresse";
-    for (var entry in list) {
-      if (entry.type != InternetAddressType.IPv4) {
-        throw "Wrong IP type";
-      }
-    }
-    port.close();
-  });
-}
-
-void main() {
-  testIPv6toIPv6();
-  testIPv4toIPv6();
-  testIPv6toIPv4();
-  testIPv4toIPv4();
-  testIPv6Lookup();
-  testIPv4Lookup();
-}