add Discard and tests to FacadeRegistry
Change the GetFactory and GetType methods so that they don't intercept IsNotFound, we'll trap that higher
We don't need the helper functions since the registry is typed now.
handle when FindMethod wants an API we don't have
Merge branch 'api-versioning-2-facade-registry' into api-versioning-3-use-registry

Bring in the updated view for FindMethod including caching, etc.
missed a couple of things we needed for resolving the merge