AUI-1173 Reload content if history state doesn't belong to us

If we detect a popstate and the state is `null`, assume it is navigating to an external page or to a page we don't have route, then `window.location.reload()` is invoked in order to reload the content to the current url.
AUI-1173 Navigate method should return true if it's able to navigate to the specified path
AUI-1173 Improve surface demo