Small frontend stuff
- Slightly improve the performance of sorting games.
- Add BGG rank as a sorting option.
- Fix a bug that on page load the extra preferences are shown only when there are none (instead of the other way around).
- When using recommended player numbers from BGG, don't recommend playing a game with only one player (except if it is only recommended as a solo game). Also generally slightly improve the underlying logic.
Edited by Robin Stoll