Summary: Ref T13513. Replaces "DifferentialInlineCommentQuery" with the similar but more modern "DifferentialDiffInlineCommentQuery".
Test Plan: Viewed comments in timeline, changesets. Created, edited, and submitted comments. Hid and un-hid comments, reloading (saw state preserved).
Maniphest Tasks: T13513
Differential Revision: https://secure.phabricator.com/D21233
