feat(dart/transform) Remove import of dart:mirrors

+ Precede the call to `new ReflectionCapabilities()` with our generated
code which populates the reflection map statically.
+ Add the import of our generated code.
+ Once we are generating all necessary code, we will remove the
import of reflection_capabilities.dart and the instantiation of
`ReflectionCapabilities`, cutting the dependency on dart:mirrors.

Closes #761

modules/angular2/test/transform/reflection_capabilities.dart

@@ -0,0 +1,9 @@
+// Copyright (c) 2013, 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 angular2.test.transform;
+
+/// Mocked out version of [ReflectionCapabilities], defined in
+/// src/reflection/reflection_capabilities.dart. Importing the actual file in
+/// tests causes issues with resolution due to transitive dependencies.
+class ReflectionCapabilities {}