Updated to WE 6 and WG 6, exported their functions.

Functions can now be found in SKCompat.
Added some remaining 1.8 mob references.
Switch to official Spigot repo
Added minecart display block to entity_spec
Merge pull request #242 from PseudoKnight/master

Add minecart display block to entity_spec
Fix Spigot repo url
Fixed NPE with pbed_location() when bed is missing or obstructed
Added item_despawn event
Fixed docs for inventory_click missing player prefilter
Merge pull request #243 from PseudoKnight/master

Fix spigot repo; Add item_despawn; Fix pbed_location NPE; Fixed inventory_click docs missing prefilter;
Added 'elder' state for guardians to entity_spec
Merge pull request #244 from PseudoKnight/master

Added 'elder' state for guardians to entity_spec
Added save_players() function
Fix environment for registered command executor closures
Handle die() in closures
Merge pull request #245 from PseudoKnight/master

Fix a couple closure issues; Add save_players()
Add ItemArray conversion for the string name.
Merge pull request #246 from jb-aero/itemnames

Add ItemArray conversion for the string name.
Merge pull request #241 from jb-aero/sk6

Updated to WE 6 and WG 6, exported their functions.
Fixed missed updates to InventoryManagement.