R1:b8cb6ddaa5bb

Add some keys and policy fields to repositories

Summary:
- Add some TODO'd keys.
- Add policy fields.

Test Plan: Viewed repositories; created a new repository and verified it got the right default policy settings.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D7056