When a lever is clicked while inside a parkour arena, that lever is saved. Once the last player leaves, or the last player restarts, the saved levers are turned off.
This change reverts the advanced hit-box detection for kill plane blocks, giving them a full block's hit-box again.
Instead, obstacle blocks have been added, which have an accurate hit-box, and can trigger a hit from any direction.
The horizontal kill plane hit box option has been removed as it's no longer useful.
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.
Adds some missing save arena method calls for parkourArena's edit methods.
Adds a message when a player reaches a new parkour checkpoint, and makes sure to avoid repeated messages.
Adds /dleave and /pleave as aliases to /minigamesleave
Fixes the win block type causing a win even when the win location is set.
Fixes the leave command only working for dropper arenas.
Fixes the command listener only cancelling command usage while in a dropper arena.
Fixes only dropper sessions being quit when the server stops.
