feat(router): user metadata in route configs

Provide the ability to attach custom data onto a route and retrieve
that data as an injectable (RouteData) inside the component.

Closes #2777

Closes #3541

modules/angular2/src/router/async_route_handler.ts

@@ -6,7 +6,7 @@ export class AsyncRouteHandler implements RouteHandler {
   _resolvedComponent: Promise<any> = null;
   componentType: Type;
 
-  constructor(private _loader: Function) {}
+  constructor(private _loader: Function, public data?: Object) {}
 
   resolveComponentType(): Promise<any> {
     if (isPresent(this._resolvedComponent)) {