R1:e9dedb0c88cd

Iterate on Maniphest reports

Summary:
- These are still slow, awkward and hideous -- but slightly better than
before.
- Allow "open" reports to be sorted.
- Add a "burn" chart/table for assessing project volatility.
- Add navigation.

Test Plan: Looked at reports.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran, epriestley

Maniphest Tasks: T923

Differential Revision: https://secure.phabricator.com/D1737