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/weapons/unarmed.rb

@@ -0,0 +1,11 @@
+create_weapon_class :unarmed, widget: -1 do
+  default_speed 4
+
+  add_style :accurate, animation: 422, block_animation: 424
+  add_style :aggressive, animation: 423, block_animation: 424
+  add_style :defensive, animation: 422, block_animation: 424
+end
+
+create_weapon :no_weapon, :unarmed, named: true do
+  # Todo factor out empty blocks
+end