Make audit only add ccs or auditors if that was the user's intended action

Summary: this plugs this at the controller level. the editor could also be more aware of the "action" and the fix could be there.

Test Plan: set some ccs, changed it to comment, made teh comment, noted no ccs.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T1838

Differential Revision: https://secure.phabricator.com/D3590