R1:e7fbfb1eacaf

Remove some old page rendering code from Diffusion

Summary: Get rid of remaining callsites for buildStandardPageResponse() and modernize the UIs.

Test Plan: Looked at branches, tags, and commit detail pages.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D7062