Add IsolateRunner as a helper around Isolate.

lib/isolate.dart

Index: lib/isolate.dart
diff --git a/lib/isolate.dart b/lib/isolate.dart
new file mode 100644
index 0000000000000000000000000000000000000000..9e838b85257d3fa33e0bc8840bef1d39fbbac293
--- /dev/null
+++ b/lib/isolate.dart
@@ -0,0 +1,14 @@
+// Copyright (c) 2015, 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.
+
+/**
+ * Utilities for working with isolates and isolate communication.
+ */
+library dart.pkg.isolate;
+
+export "isolaterunner.dart";
+export "loadbalancer.dart";
+export "ports.dart";
+export "registry.dart";
+export "runner.dart";