When the winner is overrided by external events (ArenaEndEvent), declare
the new winner.
Throw IllegalArgumentException if an invalid winner was specified.
Tidy up formatting of calculating the missing warps and notifying a
player regarding the missing warps.
Document CommandManager and all its functions.
Fix Arena set location mechanism
Fix up missing warp related issues.
Fix duplicates by converting from List to Set.
Complete overhaul of ability system.
Huge bug fixes:

- Fixed bugs with setting the first hill of an arena.
- Fixed all ability bugs during code revamp
- Fixed bugs with arena information (total players, times played, etc..)
- Fixed bugs with setting warps and hills.