Reload ban files when reloading the server. Adds BUKKIT-3470
Compensate for allow-nether/allow-end as false; Fixes BUKKIT-3466

When either of those settings are false, the worlds are not loaded and
therefore will not be targeted for portal exits.  Existing worlds are
iterated directly to avoid defaulting to the first world if a direct
dimension match is not found.

Plugins must also specify exit from custom Bukkit worlds to comply with
original commit: https://github.com/Bukkit/CraftBukkit/commit/2dc2af0

This commit introduces a constant to clarify the dependency on the
CraftBukkit implementation of custom worlds having a dimension offset.
Call BlockPlaceEvent for skulls the same as other blocks. BUKKIT-3406

When the skull BlockPlaceEvent was added it was made so the event
would be called after all the data has been set, however this is a
behavior change that is inconsistent with other BlockPlaceEvents.
Instead, if people wish to get the block data they should schedule
a task.

Relates to: BUKKIT-3438
Properly calculate level cost for books. Fixes BUKKIT-3410
Spigot
EMC POM changes
Revert mc version setting to 1.4.6 so 1.4.6 plugins still work
Remove CraftBukkit "Feature" of ItemStack's having infinite use.
Add 2 events for better control of mob spawning (Natural and Spawners)
Add PlayerUseItem Event so we can control when an item is consumed.
EMC Anvil Tweaks Make Items not have a repair cost increase due to Anvil usage. Repair only is 5 levels, combines is free renames.
Try old 1.4.5 dig speed algorithm for better results.
Load custom permissions before plugins
Entity Activation range check
Do not skip fireworks ever for ticking in loaded chunks. Thanks @mikeprimm
Target default world when returning from The End; Fixes BUKKIT-3494

Due to the having to generate new logic to avoid using the customized
PlayerConnection.moveToWorld, entities returning from The End were not
properly calculating their exit target.  This commit corrects that
logic.
Change collision skipping to only skip other living entities
Timings improvements
Fix exp merging