Cleanup vm_service library loading.

runtime/bin/vmservice/server.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.
 
-part of vmservice;
+part of vmservice_io;
 
 class Server {
   int port;
   static ContentType jsonContentType = ContentType.parse('application/json');
   final VmService service;
   HttpServer _server;
 
   Server(this.service, this.port);
 
   void _requestHandler(HttpRequest request) {
@@ skipping 45 matching lines @@
       port = s.port;
       _server = s;
       _server.listen(_requestHandler);
       if (display_message) {
         print('VmService listening on port $port');
       }
       return s;
     });
   }
 }