Add very very basic reporting to Maniphest
Summary: Rough cut for Quora, we want this too eventually but it's super basic
right now so I'm not linking it anywhere. Once we get a couple more iterations
I'll put it in the UI.
Test Plan: Looked at stats for test data.
Reviewers: btrahan
Reviewed By: btrahan
CC: anjali, aran, epriestley
Differential Revision: https://secure.phabricator.com/D1594