R1:34efbc8eb42f

Unify terminology in Differential overview

Summary:
Deja vu: D1472

Blame Rev: rP92f3ff

Test Plan: /differential/filter/revisions/

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, epriestley

Differential Revision: https://secure.phabricator.com/D1770