Don't crash on improper ~walk usage

InstantQueues, foreach/repeat, null NPCs, ... so many ways it can go
wrong!
Rework instant injections

They now manually fire instantly, rather than relying on the revolve
code to handle it. This will dodge issues related to if/else leveling.
Also, the algorithm for instant code was reworked to be less likely to
conflict with future injection code.
Apply some auto fixes

Also, fix inventory.title
Merge branch 'master' of https://github.com/mcmonkey4eva/Denizen
Fix some tag escaping, add &sp to the escape set

&sp is the only one-way-escape... you can &sp, but the escape: tag won't
ever create &sp.
Also, ensure &lt/&gt function correctly, and the log command should
clean output.
Add - inventory close

This simply closes any inventory the player has open.
Allow tags in inventory script titles and definitions

This is mostly just for colors.
Merge branch 'master' of https://github.com/mcmonkey4eva/Denizen
Update CommandRegistry, add Inventory-related meta

This sort of explains itself...
Update animatechest command, fixes #570

Unfortunately now requiring NMS packet magic... but that's better than
an awkward workaround like misusing playNote.
Merge branch 'master' of https://github.com/Morphan1/Denizen
Fix weird effects with the show_boss_bar mech

By hiding a dragon deep underground, quite similar to most of my
solutions in life.
Allow creating and saving Schematics

The schematic command now has 'create' and 'save' arguments, taking
advantage of dCuboids for the creation portion.
Repair PlaySound code, fixes #633

I hate to blame auf for things that weren't actually done by me, but...
@aufdemrand, I think you made an edit or two after testing and didn't
test those. Or didn't test at all... I don't know, but PlaySound
entirely doesn't work from that commit.
Fully working and repaired now.
Merge pull request #632 from mcmonkey4eva/master

Award-winning super pull request