Add async initialization for Intl.message and an example

pkg/intl/example/basic/basic_example_runner.dart

Index: pkg/intl/example/basic/basic_example_runner.dart
===================================================================
--- pkg/intl/example/basic/basic_example_runner.dart	(revision 0)
+++ pkg/intl/example/basic/basic_example_runner.dart	(revision 0)
@@ -0,0 +1,14 @@
+// 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.
+
+/**
+ * This is just a shell that runs the code in basic_example.dart, leaving
+ * that as a library that can also be run by tests.
+ */
+
+#import('basic_example.dart');
+
+main() {
+  setup(runProgram, print);
+}