Reorganize Element

(To fix a bug. Gotta be careful with tiny tag names like 'sub'!)
Update Rotation utilities to fit changes made to Bukkit yaws.
Fix potential problem with as: argument when invalid target is specified.
Clean up some world events dealing with entities.
Merge branch 'master' of https://github.com/aufdemrand/Denizen
Add <server.get_npcs_named[<name>]> tag.
Remove data values from dItem.identify() with aufdemrand's permission. Clean up world events dealing with items.
Add rotationthreshold argument to Fly command, to allow people to customize the turbulence of their flights.
Add "player takes item from furnace" and "entity exits portal" world events.
Add "vehicle collides", "vehicle collides with block", "vehicle collides with entity", "vehicle created" and "player places hanging" events.
Sort dEntity attributes by groups, then alphabetically. Add some missing dEntity attributes.
Fix vehicle collision events. Some minor cleanup.
Cap off substring, fixes #420
Add tags &lt and &gt
Update link in the readme
Sort dPlayer attributes by offline and online attributes, which are then sorted by groups, which are then sorted alphabetically.
Fix null projectile-related debug spam
Tiny fix.
Merge branch 'master' of https://github.com/aufdemrand/Denizen
A little formatting