R1:d4b24a2c079a

Make Ponder status changes transaction-oriented and improve rendering of transactions

Summary: Ref T3373. Use transactions for status changes.

Test Plan: {F52083}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T3373

Differential Revision: https://secure.phabricator.com/D6609