Moved theme into its own file, added message dialog state to show error messages, game install button is disabled when clicked and if there is an installer task pending or running

lib/window.rb

@@ -14,6 +14,13 @@ class W3DHub
       push_state(W3DHub::States::Boot)
     end
 
+    def update
+      super
+
+      @application_manager.start_next_available_task if @application_manager.idle?
+      current_state.update_application_manager_status if current_state.is_a?(States::Interface)
+    end
+
     def close
       @settings.save_settings