Change server's player sorting algorithm to work as the scoreboard's one, so it doesn...

Change server's player sorting algorithm to work as the scoreboard's one, so it doesn't scan all score fields but stops at the first mismatch. It required inverting score registration order and avoiding sorting scores alphabetically. While at it I tweaked score registration order a little bit.

Remove hardcoded priority list (sb_extra_sorting_field) from scoreboard's algorithm, score registration order can be used now.