Add tag list.remove[index]

Advanced list control is always useful
Make world-less locations more valid

They previously only matched with an l@ in front
Announce current script step in the debug

This looks like it was partially implemented in the past but not
finished.
Warn on no script input for the listen command

Also fix some bad meta.
Merge branch 'master' of https://github.com/aufdemrand/Denizen
Make list.get assume object type

Just like the def[] tag!
Fix enchanted books

The enchants weren't being added properly enough for Bukkit's high
taste.
Remember held script entries when forcing a queue to be timed

Forgotten when making the rest of the queue transition
Make the element.replace tag case-insensitive

Using a bit of regex magic, we can get our Denizen standard
case-insensitivity
Fix an issue with the sign changes event

Construct dLists properly
also fix a spare import
Fix potential issue with the Health Trait respawning early

Don't respawn if the respawn delay is <= 0
Also deprecate some old contexts
Default to async

So many other plugins are requiring this that it's easier to use the
dangerous async code than to tell one in every ten users they have to
use it.
Merge pull request #831 from mcmonkey4eva/master

Pull request for better debug and other things