Merge "--draft" flag and related changes from "experimental" to "master"

Summary: Ref T13010. This brings the "--draft" flag (and a handful of related flags) to "master" from "experimental".

Test Plan: Ran "arc diff". This code has been in use on "experimental" for a long time.

Maniphest Tasks: T13010

Differential Revision: https://secure.phabricator.com/D20985