[nginx] Add support for XOAUTH2 and OAUTHBEARER authentication

[Robert Mueller]

Hi

> What do you think about this approach?

Thanks for looking at this patch. My nginx coding experience is very limited, so I appreciate that you spent the time to look at it carefully. I haven't looked closely at the updated patch, but the changes you listed all sound like improvements and/or fixes which is great. I'm happy to see this integrated upstream, so that others can take advantage of it in the future.

Cheers

-- 
Rob Mueller
robm at fastmailteam.com