Boost now records per-arena statistics:
Players' win/loss statistics are now recorded both overall and separately for each game arena or map. Place holders and query commands have been extended to accommodate fetching per-arena stats as well as the previous overall stats.

New PAPI place holders:

• %boost_top_<period>_<position>_<stat>_<game>% in addition to the previous %boost_top_<period>_<position>_<stat>%
• %boost_player_<period>_<stat>_<game>% in addition to the previous %boost_player_<period>_<stat>%

Commands that were extended:

• "/boost top <period> <game>" in addition to the previous "/boost top <period>"
• "/boost stats <player> <game>" in addition to the previous "/boost stats <player>"
• "/boost delstats <player> <game>" in addition to the previous "/boost delstats <player>"
• "/boost delstats * <game>" to clear all player stats for a game arena, in addition to the previous "/boost delstats *".

Other changes:
Player display names are now updated each time statistics are recorded so that they keep up with nickname or prefix changes.
Boost stores display names rather than fetching them live so that it can show the chosen display name in leader board queries for players that are offline.