Move inline "done" checkboxing to DiffInline
Summary:
Ref T12616. This updates clicking the "Done" checkbox for the new stuff.
This one is pretty clean since the "Done" checkbox doesn't do too much weird magic.
Test Plan: Clicked the box a few times.
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T12616
Differential Revision: https://secure.phabricator.com/D17888