Add Projects to Dashboards and Panels

Summary: Making an attempt here. This adds the ability to set Projects on Dashboards and Dashboard Panels. Most of this went smooth, but I can't figure out why the queries don't automatically show searching by Projects. I'm stumped. Rest seems fine.

Test Plan: Assign a Project to a Dashboard and a Panel, see Project show up, edit it, see transactions.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D13656