Add InternetAddress:rawAddress, to return the raw address as a list of bytes.

tests/standalone/io/internet_address_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 "package:expect/expect.dart";
 
 void testDefaultAddresses() {
   var loopback4 = InternetAddress.LOOPBACK_IP_V4;
   Expect.isNotNull(loopback4);
   Expect.equals(InternetAddressType.IP_V4, loopback4.type);
   Expect.equals("127.0.0.1", loopback4.host);
   Expect.equals("127.0.0.1", loopback4.address);
+  Expect.listEquals([127, 0, 0, 1], loopback4.rawAddress);
 
   var loopback6 = InternetAddress.LOOPBACK_IP_V6;
   Expect.isNotNull(loopback6);
   Expect.equals(InternetAddressType.IP_V6, loopback6.type);
   Expect.equals("::1", loopback6.host);
   Expect.equals("::1", loopback6.address);
+  Expect.listEquals([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
+                    loopback6.rawAddress);
 
   var any4 = InternetAddress.ANY_IP_V4;
   Expect.isNotNull(any4);
   Expect.equals(InternetAddressType.IP_V4, any4.type);
   Expect.equals("0.0.0.0", any4.host);
   Expect.equals("0.0.0.0", any4.address);
 
   var any6 = InternetAddress.ANY_IP_V6;
   Expect.isNotNull(any6);
   Expect.equals(InternetAddressType.IP_V6, any6.type);
@@ skipping 80 matching lines @@
   InternetAddress.lookup("::1").then((addresses) {
     Expect.equals(1, addresses.length);
     Expect.equals("::1", addresses[0].address);
   });
 }
 
 void testReverseLookup() {
   InternetAddress.lookup('localhost').then((addrs) {
     addrs.first.reverse().then((addr) {
       Expect.isNotNull(addr.host);
+      Expect.isNotNull(addr.rawAddress);
     });
   });
 
   InternetAddress.lookup('127.0.0.1').then((addrs) {
     Expect.equals('127.0.0.1', addrs.first.host);
+    Expect.listEquals([127, 0, 0, 1], addrs.first.rawAddress);
     addrs.first.reverse().then((addr) {
       Expect.isNotNull(addr.host);
       Expect.notEquals('127.0.0.1', addr.host);
+      Expect.listEquals([127, 0, 0, 1], addr.rawAddress);
     });
   });
 }
 
 void main() {
   testDefaultAddresses();
   testConstructor();
   testEquality();
   testLookup();
   testReverseLookup();
 }