* Add IAuthorizationPolicyProvider sample
* Update IAuthorizationPolicyProvider sample to show falling back to a default provider
* Make project, directory, and namespace names consistent for custom policy provider sample
* Make policy provider sample an MVC app and replace Values controller with a home controller (with views)
* Add cookie authentication and account controller/views
* Update readme and comments to reflect new authorization policy provider scenario
* Add some more information to the access denied page for debugging purposes
* Add some additional logging
* Minor updates based on PR feedback