refactor: deprecate RootRenderer / Renderer

Use `RendererV2` instead of `Renderer` now. `Renderer` can still be injected
and delegates to `RendererV2`.

Use `RendererFactoryV2` instead of `RootRenderer`. `RootRenderer` cannot be used
anymore.

BREAKING CHANGE:
- `RootRenderer` cannot be used any more, use `RendererFactoryV2` instead.
  Note: `Renderer` can still be injected/used, but is deprecated.

modules/@angular/platform-browser/src/dom/dom_renderer.ts

@@ -50,6 +50,8 @@ export class DomRootRenderer_ extends DomRootRenderer {
       sharedStylesHost: DomSharedStylesHost, animationDriver: AnimationDriver,
       @Inject(APP_ID) appId: string) {
     super(_document, _eventManager, sharedStylesHost, animationDriver, appId);
+    throw new Error(
+        'RootRenderer is no longer supported. Please use the `RendererFactoryV2` instead!');
   }
 }