Widgets should be able to optionally expose state on the URL

[sakhmechet]

Currently the only widget that can expose state on the URL is Navigation. Widgets like Grid cannot expose state. This makes the user run into very annoying issues similar to the ones common to Expedia/Travelocity? - someone sends a link to a hotel to a friend, but the friend sees a completely different page.

As an example, grid controls should be able to optionally expose which column they're sorted on. People should be able to navigate to a product page by product name/id on the URL.

[sakhmechet]

We should consider some form of 'persistent actions' to implement this. Perhaps similar to the way we implement resetting sessions in debug toolbar?

[sakhmechet]

This may require making the navigation widget more advanced. In particular, we may need to allow "hidden" panes that only exist to service the URLs but aren't rendered. Additionally we may need to add "dynamic" panes that are created on the fly based on the URL according to some rules.

We may also need to support multiple navigation widgets in one composite.

[sakhmechet]

We should consider how 'dynamic' navigation widgets will affect 'page-title' facility.