Router: Clicking on [router-link] directives bypasses native 'onHashChange' events

This makes it impossible for third-party code (not aware of Angular) to know when the route has changed. Honestly, I'd prefer for [router-link] to go entirely away or be optional. It's a lot easier and more portable to use plain `<a href="...">` and instead have the router deal with understanding those.

For example, [router-link] only supports clicks. Not keyboard.
