Status icons for pinboards.

Summary: Adds image count and token count under the pinboard image. Extended pinboard-item-view for any icon/count pair.

Test Plan: Review Pholio and Macro, tested Chrome and IE9.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2645

Differential Revision: https://secure.phabricator.com/D5237