Better 404 handling in isomorphic app

[mathiversen]

• There seems to be a bug when navigating to the catch_all route but not contributors, ex. localhost:7878/test. The current implementation panics using both rocket and actix as server.
• Rocket currently has 404 for unknown routes and this should be added to the actix example as well.

[chinedufn]

Ah thanks for pointing this out!

[AxelNilsson]

Here's an example of what I did using the isomorphic example.

lib.rs

impl App {
    pub fn render(&self) -> VirtualNode {
        match self.router.view(self.store.borrow().path()) {
            Some(route) => route,
            None => NotFoundView::new().render(),
        }
    }
}