Summary:
Ref T13053. Adds revision stamps (status, reviewers, etc). Adds Herald rule stamps, like the existing X-Herald-Rules header.
Removes the "self" stamps, since you can just write a rule against `whatever(@epriestley)` equivalently. If there's routing logic around this, it can live in the routing layer. This avoids tons of self-actor, self-mention, self-reviewer, self-blocking-reviewer, self-resigned-reviewer, etc., stamps.
Use `natcasesort()` instead of `sort()` so that numeric values (like monograms) sort `9, 80, 700` instead of `700, 80, 9`.
Remove the commas from rendering since they don't really add anything.
Test Plan: Edited tasks and revisions, looked at mail stamps, saw stamps that looked pretty reasonable (with no more self stuff, no more commas, sorting numbers, and Herald stamps).
Reviewers: amckinley
Reviewed By: amckinley
Maniphest Tasks: T13053
Differential Revision: https://secure.phabricator.com/D18997
