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.rb

@@ -1,12 +1,28 @@
-on :message, :npc_action do |player, message|
-  player_combat_state        = get_combat_state player
-  player_combat_state.target = $world.npc_repository.get message.index
+java_import 'org.apollo.game.message.impl.HintIconMessage'
 
-  unless player.attacking
-    player.start_action CombatAction.new(player)
-  end
+on :message, :npc_action do |player, message|
+  target                     = $world.npc_repository.get message.index
+
+  # unless target.attacking
+  #   target_combat_state        = get_combat_state target
+  #   target_combat_state.target = player
+  #
+  #   target.start_action CombatAction.new(target)
+  # end
+
+  player_combat_state        = get_combat_state player
+  player_combat_state.target = target
+
+  player.send HintIconMessage.for_npc(target.index)
+  player.walking_queue.clear
+  player.start_action CombatAction.new(player) unless player_combat_state.is_attacking?
 end
 
 on :message, :player_action do |player, message|
-  
-end
+
+end
+
+schedule 0 do |_task|
+  $world.player_repository.each { |player| player.attack_timer = player.attack_timer + 1 }
+  $world.npc_repository.each { |npc| npc.attack_timer = npc.attack_timer + 1 }
+end