Show drafts and inline comments

Summary:
Show drafts for users that made them.
Show inline comments beside image, highlights them when user mouseovers selection.
Allow users that can view mock to add inline comment instead of only allowing users that can edit mock to add inline comment.

Test Plan:
Verified that inline comments are shown beside image. Verified that only drafts for current user are shown. Verified that inline comment is
highlithed when user mouseovers their selection.

Reviewers: epriestley

CC: aran, Korvin

Maniphest Tasks: T2446

Differential Revision: https://secure.phabricator.com/D4929