Fixes T2543. This mode has been a stable prototype for a very long time now; promote it so "--draft" can promote out of "experimental" in Arcanist.
- Maniphest Tasks
- T2543: Add a formal "Draft" / "Not Yet Ready for Review" state to Differential
- rPdc35ce79e484: Unprototype "Draft" mode in Differential
See T2543 for discussion.