Summary:
Fixes T5135. Currently, when you create a credential, we default the policies to your PHID. This means we can't have an application-level configurable default because there's no way to select "the actor's PHID" as a policy.
Start tracking the credential author's PHID and add an object policy for it, so there is such a setting.
Then, add policy defaults.
This mostly unblocks T6787. This obsoletes T6860.
Test Plan:
- Created a credential with "Credential Author" policy.
- Verified I can see/edit it, but other users can not.
- Changed default policies to something else.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T5135
Differential Revision: https://secure.phabricator.com/D13385
