Implement arc audit, which triggers audits. Rough plan is:
- Do a future-proofing check:
- have the workflow check for diffusion.createcommit using conduit.query;
- or just give up and accept the X.createcommit APIs indefinitely.
- Look up users with user.query to get their PHIDs.
- Look up commit PHIDs with diffusion.querycommits or similar. This needs to be implemented, and will deprecate diffusion.getcommit.
- Call diffusion.createcomment to create the audit.
- Needs a tweak to accept auditor PHIDs.