Add ranged combat support

* Clean up the CombatAction and Attack code to make it easier to use for
  range.

* Add collision detection to the distance checks before attacking in the
  CombatAction.

* Create a Ruby DSL for defining projectile types and fix the
  ProjectileUpdateOperation so it uses the correct position offset.

* Fix the packet structure of the HintIconMessageEncoder.

data/plugins/combat/combat_state.rb

@@ -1,7 +1,7 @@
 def get_combat_state(mob)
   mob.is_a?(Player) ? type = :player : type = :npc
 
-  unless MOB_COMBAT_STATE_CACHE[type].has_key? mob.index
+  unless MOB_COMBAT_STATE_CACHE[type].key? mob.index
     MOB_COMBAT_STATE_CACHE[type][mob.index] = CombatState.new(mob)
   end
 
@@ -11,8 +11,7 @@ end
 private
 
 class CombatState
-  attr_accessor :state
-  attr_reader :queued_attacks, :supports_weapon
+  attr_reader :target
 
   def initialize(mob, supports_weapon = true)
     @mob             = mob
@@ -21,20 +20,22 @@ class CombatState
   end
 
   def reset
-    @state          = :idle
     @target         = nil
     @next_attack    = nil
     @queued_attacks = []
-    @mob.reset_interacting_mob
   end
 
-  def target
-    @target
+  def will_attack?
+    is_attacking? && next_attack(true).speed >= @mob.attack_timer
+  end
+
+  def is_attacking?
+    !target.nil? && @mob.attacking
   end
 
   def target=(target)
     @mob.reset_interacting_mob
-    @mob.interacting_mob = target
+    @mob.interacting_mob = target unless target.nil?
     @target              = target
   end
 
@@ -44,23 +45,25 @@ class CombatState
 
   def next_attack(peek = false)
     if @queued_attacks.size > 0
-      peek ? @queued_attacks.first : @queued_attacks.pop
+      peek ? @queued_attacks.last : @queued_attacks.pop
     else
       weapon = EquipmentUtil.equipped_weapon @mob
 
-      if @mob.using_special and weapon.special_attack?
+      if @mob.using_special && weapon.special_attack?
         weapon.special_attack
       else
-        weapon_class = weapon.weapon_class
-        combat_style = weapon_class.style_at @mob.combat_style
-        
-        weapon_class.attack combat_style
+        combat_style = weapon.weapon_class.selected_style @mob
+        combat_style.attack
       end
     end
   end
 end
 
 MOB_COMBAT_STATE_CACHE = {
-  :player => {},
-  :npc    => {}
+  player: {},
+  npc:    {}
 }
+
+on :logout do |event|
+  MOB_COMBAT_STATE_CACHE[:player].delete event.player.index
+end