Specify a default route to handle unmatched routes

[jakewhiteley]

There is currently no way to specify what happens on an unmatched route.

I propose a user should be able to set this as part of view.options as follows:

App.View('404', {
    options: {
        defaultRoute: true
    }
}

This will allow a application to specify it's 404 view, or pass a bad request to the home page for example.

[astoilkov]

This is a must. I have added as a feature for the upcoming 0.4.0 release.