Extract common code, add host IP to --debug and --enable-vm-service options

dart/runtime/bin/vmservice/vmservice_io.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.
 
 library vmservice_io;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'dart:isolate';
 import 'dart:vmservice';
 
 part 'resources.dart';
 part 'server.dart';
 
-// The TCP port that the HTTP server listens on.
+// The TCP ip/port that the HTTP server listens on.
 int _port;
+String _ip;
 
 // The VM service instance.
 VMService service;
 
 main() {
   // Get VMService.
   service = new VMService();
   // Start HTTP server.
-  var server = new Server(service, _port);
+  var server = new Server(service, _ip, _port);
   server.startServer();
 }