Render "Show Context" blocks in unified view
Summary:
Ref T2009. This basically copy/pastes them for now. Plans is:
- Make this actually work all the way.
- Add test coverage after D11970.
- Move 2-up here after test coverage.
Clicking the links does not work yet, because they use the 2-up renderer. I'll fix this in the next diff.
Test Plan: Viewed diffs in unified, saw links to show more.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: chad, epriestley
Maniphest Tasks: T2009
Differential Revision: https://secure.phabricator.com/D11976