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.
Abstractions - Core MVC extensibility
Controllers - MVC implementations of .Abstractions and supporting
contracts
Infrastructure - General purpose support APIs. Metadata APIs that don't
fit clearly with a feature or with .Abstraction
Ryan Nowak
N. Taylor Mullen
sornaks