Control which blocks can be used for shop container

#The list of blocks that can be used to create shops.
#By default, chests are added to this list.
#This will only work for blocks that implement an InventoryHolder!
#In other words, You cannot create shops with normal blocks like dirt or stone.
#Enderchests can only be used as shop blocks when the "openinv" plugin is installed!
#May cause unexpected behavior with some blocks...eg:
#-Hopper shops suck the display item in, 
#-Furnace shops allow players whatever item they want in all 3 slots,
#-Dispenser shops aren't protected from redstone,
#-Etc...
shop-blocks:
  - CHEST
  - TRAPPED_CHEST
  - ENDER_CHEST