Summary: created a PhabricatorInlineCommentPreviewController so controllers in Diffusion and Differential respectively just have to handle the URI mapping and data loading like good little controllers.
Test Plan:
left inline comments on commits, deleted inline commits, submitted inline comments -- all worked well
did the same on some diffs
Reviewers: epriestley
Reviewed By: epriestley
CC: aran, Korvin
Maniphest Tasks: T1176
Differential Revision: https://secure.phabricator.com/D3034
