Prevents players from placing blocks outside the world border. Default
off.
This is for the PrisonPearl plugin, where if a player is imprisoned in a
chest placed far enough outside the world border it becomes impossible
to break the chest and free the player.
The BlockPlaceEvent listener is only registered if the option is
enabled.
Some further changes as well, including some minor code design improvement. As part of that, the root plugin's GetWorldBorder(String worldName) method has been deprecated and replaced with proper first-letter capitalization: getWorldBorder(String worldName).
All commands have now been tested in-game and through console, and a couple of remaining command bugs have been fixed.