Split dart:builtin into dart:builtin and dart:io.

frog/server/frog_server.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, 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('frog_server');
 
+#import('dart:io');
 // TODO(devoncarew): importing this file is temporary until dart:json is resolved
 #import('dart_json.dart');
 #import('../lang.dart');
 #import('../file_system_vm.dart');
 #source('utf8.dart');
 
 /// The server socket used to listen for incoming connections.
 ServerSocket serverSocket;
 
 initializeCompiler(String homedir) {
@@ skipping 131 matching lines @@
 main() {
   // TODO(jmesserly): until we have a way of getting the executable's path,
   // we'll run from current working directory.
   var homedir = new File('.').fullPathSync();
 
   var argv = new Options().arguments;
   var host = argv.length > 0 ? argv[0] : '127.0.0.1';
   var port = argv.length > 1 ? Math.parseInt(argv[1]) : 1236;
   startServer(homedir, host, port);
 }