In the docs, it's noted that this is providing support for OAuth 2.0, draft 16. The spec is now on to draft 20, and there appear to be significant changes to the spec in draft 17, changes that appear (based on a superficial scan) to affect the authorization workflow. I haven't yet reviewed all the changes, as I'm not very familiar with the spec, nor its perturbations. Are you aware of the updates to the spec, are they substantive, and are you planning to support the spec in its final form?