* Add a gap between thumbnails on mobile.
* Adjust CSS for scores and vote buttons.
* Include "Private favorites" as an incentive on the user upgrade page.
* Fix vote buttons not being visible beneath thumbnails on mobile.
* Fix the "Show scores" link not preserving the current page number.
* Fix vote buttons being unintentionally enabled for all thumbnails by default.
* Fix banned and restricted users being able to favorite posts by
tagging them with `fav:self`.
* Fix search engines being able to crawl /posts?view=score pages.
* Fix broken tests.
* Factor out the post navbar into a component. The post navbar is the
part of the post containing the current search, the list of pools, and
the list of favgroups, along with next/prev navigation links.
* Change navbar markup: remove various unused CSS classes/IDs, change
pools to use same markup as favgroups, replace nested <div>'s with
flat <ul>/<li> list.
* Use CSS to truncate long searches/pool names/favgroup names if they're
too wide for the screen (especially on mobile).