Allow Fact app to draw charts

Summary: For any count fact, allow a chart to be drawn. INCREDIBLY POWERFUL DATA ANALYSIS PLATFORM.

Test Plan: Drew a chart of object counts. Drew the Maniphest burn chart.

Reviewers: vrana, btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1562

Differential Revision: https://secure.phabricator.com/D3099