Routing plans

Some plans for routing.
- Routing will be data-and-template based. Routes will fetch data then render a template. Unlike Ember, any number of data sources can be fetched for each route (like the UI-Router)
- Nested routes will look for places to be inserted within parent route templates (as in both UI-Router and Ember)
- Routing will be state-based and optionally URL-based, not URL-based. This means that applications that don't encode their state in a URL bar will still be able to use the router.
- Templated routing will be done via a `link-to` Handlebars helper.
- Programmatic routing will be done by name. `routeTo('myNamedRoute', myRouteParams);`

No files, tests, or entry points are named. Start by locating the existing routing and template architecture, then compare it with the stated data-based, nested, state-based, named, and Handlebars link-to plans. Done would require an agreed design and implementation scope; the issue does not define a bounded first change.

Written by the indexing model from the issue text.