Reduce number of times the inside table needs to be indexed or have length checked.
Also assign debug zones to table without having to be inside the zone.
lib.zones.new should take a single argument containing all
data related to the new zone, then append new fields to the table.
No need for a distance check and 'nearby', instead check if player
is inside the polygon.
Use a function ref instead of closures for debug (drawPolygon).