R1:a3a5176b7e17

Add basic countdown timer to object list

Summary: Allows a rough setting of a number and noun for object item list view.

Test Plan:
Use in countdown, set various times.

{F670267}

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D13742