New icons, colors for per reviewer status

Summary: Fixes T10906, Fixes T10820. Adds new icons, grey-er colors for previous states. Also, I think fixed a few bugs?

Test Plan: Fake each state, verify icon is as intended.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T10820, T10906

Differential Revision: https://secure.phabricator.com/D15830