Return 404 error if access to non existent path

[HIRANO-Satoshi]

Currently 200 is returned and consumes download bandwidth.

[HIRANO-Satoshi]

We have this in app.yaml. No problem.

All other routes to the bundle for pushState

• url: .* secure: always static_files: app-dist/index.html upload: app-dist/index.html

Luncho app is a Single Page App (SPA). We have '/' as the fallback. No problem.

    configureRouter(config: RouterConfiguration, router: Router) {
    ...
        config.map([
            { route: ['', 'countries'], href: '/countries', name: 'countries',
              moduleId: PLATFORM.moduleName('./countries'),
              auth: true, nav: true, title: 'All countries', },
            { route: 'single', href: '/single', name: 'single',
              moduleId: PLATFORM.moduleName('./single'),
              auth: true, nav: true, title: 'One country', },
            { route: 'about', href: 'about', name: 'about',
              moduleId: PLATFORM.moduleName('./about'),
              auth: true, nav: false, title: 'About', },

        ]);

        config.fallbackRoute('/');

The problem is that bundles are not cached within the browser.