Summary: Adds Workboards and workpanels. This is a preliminary diff, I'm still working on mobile and tablet and a few missing features (header actions)
Test Plan: FF, Chrome, iOS, iPad, iPhone, IE
Reviewers: epriestley
Reviewed By: epriestley
CC: aran, Korvin
Differential Revision: https://secure.phabricator.com/D5455
