Add access to parameters of a child root to the RouteProvider

[michalpie]

Let us consider the recipe application described here: #837

value(RouteInitializerFn, (r, views) {
  views.configure({
    'recipes': ngRoute(
        path: '/recipes',
        view: 'recipes.html',
        mount: {
          'view': ngRoute(
              path: '/:recipeId/view',
              view: 'view.html'),
          'edit': ngRoute(
              path: '/:recipeId/edit',
              view: 'edit.html')
        })
  });
});

There is a list of recipes in an ng-view (recipes.html) and in another, nested ng-view the selected recipe is displayed.

Currently there is no easy way to highlight actually selected recipe in recipes.html. If a RouteProvider is attached to the recipes.html it does not have access to recipeId parameter.

[mhevery]

@pavelgj can you look into this?

[pavelgj]

This can be moved to https://github.com/angular/route.dart -- not angular FR