This change introduces ControllerContext for inside of Controllers, and
controller-specific extensibility points. ControllerContext carries with
it the model binding infrastructure needed to do all of the things that
controllers need to do.
This is the MVC companion to https://github.com/aspnet/Routing/pull/122
As routing flows, routes replace the route data and mutate a copy. This
allows users to make changes that dirty the data without affecting
undesired state changes.
We also add the 'next' router for diagnostic purposes.
James Newton-King
jacalvar
N. Taylor Mullen
Ryan Nowak