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

frog/server/frog_server.dart

Index: frog/server/frog_server.dart
diff --git a/frog/server/frog_server.dart b/frog/server/frog_server.dart
index e7bfe29e2135d15c963f682ace0e62b720260b17..9efdde7a8eab3dc8624b495672a79b2159e5cbdf 100755
--- a/frog/server/frog_server.dart
+++ b/frog/server/frog_server.dart
@@ -1,9 +1,10 @@
-// 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');