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/combat_state.rb

@@ -0,0 +1,49 @@
+def get_combat_state(mob)
+  mob.is_a?(Player) ? type = :player : type = :npc
+
+  unless MOB_COMBAT_STATE_CACHE[type].has_key? mob.index
+    MOB_COMBAT_STATE_CACHE[type][mob.index] = CombatState.new(mob)
+  end
+
+  MOB_COMBAT_STATE_CACHE[type][mob.index]
+end
+
+private
+
+class CombatState
+  attr_accessor :state, :next_attack
+  attr_reader :queued_attacks, :supports_weapon
+
+  def initialize(mob, supports_weapon = true)
+    @mob             = mob
+    @supports_weapon = supports_weapon
+    reset
+  end
+
+  def reset
+    @state          = :idle
+    @target         = nil
+    @next_attack    = nil
+    @queued_attacks = []
+    @mob.reset_interacting_mob
+  end
+
+  def target
+    @target
+  end
+
+  def target=(target)
+    @mob.reset_interacting_mob
+    @mob.interacting_mob = target
+    @target              = target
+  end
+
+  def queue_attack(attack)
+    @queued_attacks.push(attack)
+  end
+end
+
+MOB_COMBAT_STATE_CACHE = {
+  :player => {},
+  :npc    => {}
+}