R1:ada5f81614b8

Display 'away until' in owners and revision comment

Summary: It would be best to add this everywhere at once but I'm too lazy for it.

Test Plan: Displayed package list and detail and revision comment with away users.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3419