Bukkit

• Two new variations of the set command are available thanks to sponsorship from Rhythmatic: /wb [world] set <radiusX> [radiusZ] spawn - uses the world's spawn point. /wb set <radiusX> [radiusZ] player <name> - centers a border on the specified player.
• Added new command /wb denypearl <on/off> to toggle existing "deny-enderpearl" option on or off, which requires the new permission worldborder.denypearl to use. Changed this existing "deny-enderpearl" config setting to only deny ender pearls which are thrown past the border, and switched it to be enabled by default.
• Added TeleportCause.PLUGIN indicator to the teleport methods used by border knockback, so other plugins can see that the teleport was triggered by a plugin and potentially not interfere if they otherwise would have. Specifically, this should take care of CombatTag preventing WorldBorder knockback if the player is considered to be in combat.
• Added config option "fill-memory-tolerance" which defaults to 500. If/when the Fill process pauses due to low memory (<200 MB), this setting is the amount of free memory (in MB) required to be available before it automatically continues. This option isn't made available to change through a command as most people shouldn't change it. It's been made available for people who are running extremely low memory (and thus necessarily tiny) servers which have less than 768 MB memory available to their CraftBukkit server.
• Some minor code refactoring and cleanup. (by Zeluboba)

New commands:
/wb [world] set <radiusX> [radiusZ] spawn - uses the world's spawn point.
/wb set <radiusX> [radiusZ] player <name> - centers a border on the specified player.
/wb denypearl <on/off> - toggle option which cancels ender pearls which are thrown past the border, rather than just adjusting their target location. Requires permission worldborder.denypearl.