Restore Maniphest status transactions for burnup chart purposes

Summary: The "burnup chart" relies on these to determine when tasks opened and we recently stopped writing them. Keep writing them for now. They're fluff and don't show up in the UI, but draw the right chart.

Test Plan: Saw chart go up when I made tasks.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D8682