some minor changes

include/nana/gui/layout_utility.hpp

@@ -1,14 +1,13 @@
 /*
  *	Utility Implementation
- *	Copyright(C) 2003-2013 Jinhao(cnjinhao@hotmail.com)
+ *	Nana C++ Library(http://www.nanapro.org)
+ *	Copyright(C) 2003-2015 Jinhao(cnjinhao@hotmail.com)
  *
  *	Distributed under the Boost Software License, Version 1.0. 
  *	(See accompanying file LICENSE_1_0.txt or copy at 
  *	http://www.boost.org/LICENSE_1_0.txt)
  *
  *	@file: nana/gui/layout_utility.hpp
- *
- *	
  */
 
 #ifndef NANA_GUI_LAYOUT_UTILITY_HPP

include/nana/gui/widgets/widget.hpp

@@ -12,12 +12,10 @@
 
 #ifndef NANA_GUI_WIDGET_HPP
 #define NANA_GUI_WIDGET_HPP
-#include <nana/traits.hpp>
 #include "../basis.hpp"
 #include "../programming_interface.hpp"
 #include <nana/internationalization.hpp>
 #include <nana/gui/detail/drawer.hpp>
-#include <nana/gui/layout_utility.hpp>
 #include <functional>
 
 namespace nana

source/gui/widgets/listbox.cpp

@@ -13,6 +13,8 @@
 
 #include <nana/gui/widgets/listbox.hpp>
 #include <nana/gui/widgets/scroll.hpp>
+
+#include <nana/gui/layout_utility.hpp>
 #include <nana/gui/element.hpp>
 #include <list>
 #include <deque>

source/gui/widgets/picture.cpp

@@ -13,6 +13,7 @@
  */
 
 #include <nana/gui/widgets/picture.hpp>
+#include <nana/gui/layout_utility.hpp>
 #include <nana/paint/image.hpp>
 #include <nana/gui/element.hpp>