Summary: Ref T2230. This cleans up D7442, by using `git for-each-ref` everywhere we can, in a basically reasonable way.
Test Plan:
In bare and non-bare repositories:
- Ran discovery with `bin/repository discover`;
- listed branches on `/diffusion/X/`;
- listed tags on `/diffusion/X/`;
- listed tags, branches and refs on `/diffusion/rXnnnn`.
Reviewers: btrahan, avivey
Reviewed By: avivey
CC: aran
Maniphest Tasks: T2230
Differential Revision: https://secure.phabricator.com/D7447
