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/bonuses.rb

@@ -0,0 +1,44 @@
+module Combat
+  # A module for units which can have their own bonuses. E.G., weapons, equipment, ammo.
+  module BonusContainer
+    def attack_bonus(type)
+      @attack_bonuses[type]
+    end
+
+    def defence_bonus(type)
+      @defence_bonuses[type]
+    end
+
+    def other_bonus(type)
+      @other_bonuses[type]
+    end
+
+    def other_bonuses(melee_strength: 0, ranged_strength: 0, prayer: 0)
+      @other_bonuses = {
+        :melee_strength  => melee_strength,
+        :ranged_strength => ranged_strength,
+        :prayer          => prayer
+      }
+    end
+
+    def defence_bonuses(stab: 0, slash: 0, crush: 0, magic: 0, range: 0)
+      @defence_bonuses = {
+        :stab  => stab,
+        :slash => slash,
+        :crush => crush,
+        :magic => magic,
+        :range => range
+      }
+    end
+
+    def attack_bonuses(stab: 0, slash: 0, crush: 0, magic: 0, range: 0)
+      @attack_bonuses = {
+        :stab  => stab,
+        :slash => slash,
+        :crush => crush,
+        :magic => magic,
+        :range => range
+      }
+    end
+  end
+end