HOLD: Feedback faves and flags

This is the PR for the feedback faves and flags.

See: https://github.com/GigaOM/gigaom/milestones/Comment%20redesign%20v3:%20faves%20and%20flags
We need to `esc_url( $link )`.  We probably also need to `esc_html()` or `wp_kses_post()` the `sprintf` value depending on what it contains.