Metadata is not meant to persist reload as things break badly with non primitive types
This will invalidate metadata on reload so it does not crash everything if a plugin uses it.
Under previous behavior, plugins were not able to check if a player had a permission
if it was defined in permissions.yml. there is no clean way for a plugin to fix that either.
This will change the order so that by default, permissions.yml loads BEFORE plugins instead of after.
This gives plugins expected permission checks.
It also helps improve the expected logic, as servers should set the initial defaults, and then let plugins
modify that. Under the previous logic, plugins were unable (cleanly) override permissions.yml.
A config option has been added for those who depend on the previous behavior, but I don't expect that.
Sometimes a chunk region file is closed prematurely, resulting in a "Stream Closed" error on chunk saving.
Ultimately there is a race condition that causes it, but re-trying the save will avoid the issue.
Retry the save 5 times to try our best to avoid rollbacks due to chunk save failures.
Entities collision is checking for scoreboards setting.
This is very heavy to do map lookups for every collision to check
this setting.
So avoid looking up scoreboards and short circuit to the "not on a team"
logic which is most likely to be true.
I don't know what the person who wrote that code was smoking, but I
don't think it was good.
Gets rid of the WeakHashMap that mojang was abusing purely to be lazy
on clean up, and handles registering and deregistering navigation
upon world add/remove operations.
People are able to abuse the way Bukkit handles teleportation across worlds since it provides a built in teleportation safety check.
To abuse the safety check, players are required to get into a location deemed unsafe by Bukkit e.g. be within a chest or door block. While they are in this block, they accept a teleport request from a player within a different world. Once the player teleports, Minecraft will recursively search upwards for a safe location, this could eventually land within a player's skybase.
Example setup to perform the glitch: http://puu.sh/ng3PC/cf072dcbdb.png
The wanted destination was on top of the emerald block however the player ended on top of the diamond block. This only is the case if the player is teleporting between worlds.
