Add shops support.

data/plugins/shops/shop.rb

@@ -0,0 +1,28 @@
+require 'java'
+
+java_import 'org.apollo.game.model.inv.Inventory'
+
+# A shop containing items that can be sold.
+class Shop
+  attr_reader :buys, :currency, :items, :inventory, :name, :npc_options
+
+  def initialize(name, items, currency, options, buys)
+    @name = name
+    @items = items
+    @currency = currency
+    @buys = buys
+    @npc_options = options
+    @inventory = Inventory.new(DEFAULT_CAPACITY, Inventory::StackMode::STACK_ALWAYS)
+
+    items.each { |item| @inventory.add(item.id, item.amount) }
+  end
+
+end
+
+private
+
+# The `Currency` used by default.
+DEFAULT_CURRENCY = Currency.new(995, 'money')
+
+# The default capacity of a shop.
+DEFAULT_CAPACITY = 30