R1:dccce146211b

Update misc bits of Ponder to TwoColumnView

Summary: Brings in the new headers, layout into Ponder History, editing.

Test Plan: Edit Question, Edit Answer, Question History, Answer History

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D15530