Makes sure to save the arena after editing allowed or loss trigger damage causes
Makes sure to save and restore player saturation
Adds damage animation and damage sound when faking damage for allowed damage causes
Plays a sound when a player loses
It was found that the Spigot API's methods for cancelling player collisions won't work without changing the scoreboard. Because of that, the normal option has been disabled. The invisibility option has also been removed, as that's a bad idea if players can still push each-other.
The toggle player option which is implemented in this commit does disable player collision, so that's the only working way right now.
A potential ConcurrentModificationException has been fixed.
The parkourCheckpoint command has been removed, as the functionality is now available through the API.
