Build a framework for a maintainable combat plugin

* Uses a hierarchy of WeaponClasses -> Weapons for performing attacks,
  with WeaponClass having a set of styles and associated Attacks for
  those styles. Weapons and their classes are built with an easy to use
  and clean DSL.

* Adds a BonusContainer mixin, so that Equipment, Weapons, and
  WeaponClasses can all have their own set of bonuses which apply to the
  player.

* Allows attacks to be queued to the Mobs CombatState instance from
  external code, allowing e.g., NPCs or auto-cast to queue attacks to be
  executed.

data/plugins/combat/equipment.rb

@@ -0,0 +1,18 @@
+java_import 'org.apollo.cache.def.EquipmentDefinition'
+
+EQUIPMENT = {}
+
+def create_equipment(item, &block)
+  equipment = Equipment.new
+  equipment.instance_eval block
+
+  find_entities :item, item do |equipment_item|
+    EQUIPMENT[id] = equipment
+  end
+end
+
+private
+
+class Equipment
+  include Combat::BonusContainer
+end