Add support for combat related UI

* Allows switching between different combat styles, and updates the
  combat tabs styles for every equipped weapon. If a weapon with a
  special attack is equipped, the special bar for that interface will be
  shown.

* Adds a scheduled task which periodically restores special energy to
  the player and updates their special bar.

data/plugins/combat/widgets/special_bar.rb

@@ -0,0 +1,23 @@
+java_import 'org.apollo.game.message.impl.ConfigMessage'
+
+def update_special_bar(player)
+  player.send(ConfigMessage.new(300, player.special_energy * 10)) # special energy
+  player.send(ConfigMessage.new(301, player.using_special ? 1 : 0)) # special enabled
+end
+
+on :login do |event|
+  player = event.player
+
+  update_special_bar player
+
+  schedule 25 do |task|
+    unless player.is_active
+      task.stop
+      next
+    end
+
+    player.special_energy = [player.special_energy + 5, 100].min
+    update_special_bar player
+  end
+end
+