Summary: Ref T7626. Modernizes the code a bit here so we can eventually make progress on T7626 and other stuff.
Test Plan: made a blog, edited a blog, made errors - stuff looked good
Reviewers: epriestley
Reviewed By: epriestley
Subscribers: Korvin, epriestley
Maniphest Tasks: T7626
Differential Revision: https://secure.phabricator.com/D12849
