Summary:
Ref T10784. Currently, if you terminate SSL at a load balancer (very common) and use HTTP beyond that, you have to fiddle with this setting in your premable or a `SiteConfig`.
On the balance I think this makes stuff much harder to configure without any real security benefit, so don't apply this option to intracluster requests.
Also document a lot of stuff.
Test Plan: Poked around locally but this is hard to test outside of a production cluster, I'll vet it more thoroughly on `secure`.
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T10784
Differential Revision: https://secure.phabricator.com/D15696
66366137ff