There's now a WebAPICapabilitiesHook that extensions can use to register a set of web API capabilites. This handles registering, and unregistering the sets of web API capabilities.

Also Provides documentation and sample code for the newly created WebAPICapabilitiesHook.

Unit test have been written to make sure that Capabilities are registered and unregistered properly. The third unit test checks that None cannot be registered as a key. The fourth unit test also checks that none of the default capabilities can be changed or removed.