R1:d06129b81ef7

Add setEpoch() and onboard staleness to ObjectItemListView

Summary: Fixes T3486. I don't love how this looks -- maybe we could try different icons? Like white icons on a brighter red/yellow background?

Test Plan: {F56299}

Reviewers: chad, btrahan

Reviewed By: chad

CC: aran

Maniphest Tasks: T3486

Differential Revision: https://secure.phabricator.com/D6833