Add Resource package.

lib/resource.dart

Index: lib/resource.dart
diff --git a/lib/resource.dart b/lib/resource.dart
index dbed97a36840c5cd3035a02baa26bb4a2b711bc3..b23d220637065e1ddbbcf0283b3c1f50c03a4ad1 100644
--- a/lib/resource.dart
+++ b/lib/resource.dart
@@ -1,12 +1,11 @@
-// 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.
-
-/// A [Resource] is data that can be loaded into a Dart program.
-///
-/// This library provides an implementation of [Resource] and a
-/// [PackageResolver] that controls how package: URIs are converted to
-/// URIs that can be loaded.
-library resource;
-
-export "src/resource.dart" show Resource, PackageResolver;
+// 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.
+
+/// A [Resource] is data that can be loaded into a Dart program.
+///
+/// A resource is identified by a URI.
+library resource;
+
+export "src/resource.dart" show Resource;
+export "src/loader.dart" show ResourceLoader;