Feature: Event Hooks for Failed Authentication / Authorization

[justinsa]

When a user is not authenticated an event should be fired to indicate this event has occurred. The application can then respond to that event in a specific way, such as a displaying a message about the user needing to authenticate.

When a user is not authorized an event should be fired to indicate this event has occurred. The application can then respond to that event in a specific way, such as displaying a message about the user needing elevated authorization and how they can gain such credentials.

In both cases this will allow for a significantly better customization of the experience beyond just a simple redirect to a page.

The event will be broadcast after the location change is triggered so the application can override the location change.

[justinsa]

Feature is in mainline. Will be published in next release.