Increase finesse of inline comments in Pholio

Summary:
  - Hide inline areas on mobile, and when the mouse cursor is not on the stage.
  - Show small icon markers instead of areas.
  - Yellow icons show draft comments; pink icons show final comments.

Test Plan: {F166544}

Reviewers: chad

Reviewed By: chad

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D9536