These commands enable item usage while an npc is running. When enable_items is
run, items can be used during scripts until disable_items is called.
To avoid possible exploits, when enable_items is invoked, it will only enable
item usage while running that script in particular. Note that if a different
script also calls enable_items, it will override the last call (so you may
want to call this command at the start of your script without assuming the
effect is still in effect).