Revert "Revert "Fix for issue 85 - Dictionary types should return null on key not found""

This is reverting the revert. We're going to go ahead with this change and
work around it in MVC.

This reverts commit 0e826e69e69a90f96444b912a188c2bf234da35d.
Routing Logging
Added scoped logging to RouterMiddleware, RouteCollection, and
TemplateRoute.