R1:dbadfeb6b756

Give dashboards basic rendering and Ajax support

Summary: Ref T3583. Let dashboards "render", sorta.

Test Plan: {F149187}

Reviewers: chad, btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T3583

Differential Revision: https://secure.phabricator.com/D8917