Fix comments in the diff viewer.
Review Request #4677 — Created Oct. 2, 2013 and submitted
Fix comments in the diff viewer.
When I refactored everything to let the diff viewer change revisions without
reloads, I broke comments on the diff page pretty hard. This change fixes it
and cleans things up a bit.
Verified that I could see comment flags (and the associated comment
tooltips/dialogs) on the diff page for various revisions and interdiffs.