Allow direct access to provider detail view

Visiting a URL like /#providers/:id should result in showing the
provider detail view.  This wasn't happening because the event
handling/routing was wired up to only consider the case where a
consumer would click on a detail link.

Change the provider links to use hash-based URLs, get rid of the
click event handlers inside ProviderListView and instead let
handlers bound to router events handle toggling elements.  This
actually ends up being a lot cleaner.