Better dialog for 3rd party auth
The mechanism used in #3748 (closed) to disable 3rd party auth currently will cause the browser to repeatedly throw http auth prompts at the user if a site attempts to use auth.
My view is that while this is confusing, at least it is better than sites silently failing. At least it might clue users into filing bugs.
We should try to find a way to replace/augment this dialog for the 3rd party case though.