refactor(shadow_dom): remove ShadowDomStrategy in favor of @View(encapsulation)

BREAKING CHANGES:
- `ShadowDomStrategy` was removed. To specify the encapsulation of a component use `@View(encapsulation: ViewEncapsulation.NONE | ViewEncapsulation.EMULATED | ViewEncapsulation.NATIVE)`
- The default encapsulation strategy is now `ViewEncapsulation.EMULATED` if a component contains styles and `ViewEncapsulation.NONE` if it does not. Before this was always `NONE`.
- `ViewLoader` now returns the template as a string and the styles as a separate array

modules/angular2/render.ts

@@ -14,5 +14,6 @@ export {
   RenderViewWithFragments,
   DomRenderer,
   DOCUMENT_TOKEN,
+  APP_ID_TOKEN,
   DOM_REFLECT_PROPERTIES_AS_ATTRIBUTES
 } from './src/render/render';