Merge branch 'feature-group' into develop

Conflicts:
	build/vc2013/nana.vcxproj
	build/vc2013/nana.vcxproj.filters

include/nana/gui/widgets/group.hpp

@@ -0,0 +1,48 @@
+/**
+ *	A group widget implementation
+ *	Nana C++ Library(http://www.nanaro.org)
+ *	Copyright(C) 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/widgets/group.hpp
+ *
+ *	@contributors: Stefan Pfeifer (st-321), Jinhao, Ariel Vina-Rodriguez (qPCR4vir)
+ *
+ *	@brief group is a widget used to visually group and layout other widgets.
+ */
+
+#ifndef NANA_GUI_WIDGETS_GROUP_HPP
+#define NANA_GUI_WIDGETS_GROUP_HPP
+
+#include <nana/gui/place.hpp>
+#include <nana/gui/widgets/button.hpp>
+#include <nana/gui/widgets/panel.hpp>
+#include <nana/gui/widgets/label.hpp>
+#include <nana/gui/drawing.hpp>
+
+namespace nana{
+    class group
+	    : public panel<true>
+    {
+	    place        plc_outer{*this};
+        panel<false> content  {*this};
+        label        titel/*  {*this}*/;
+        place        plc_inner{content};
+	    unsigned int gap;
+    public:
+        group( window    parent,         ///< 
+               string    titel_ ={STR("")},     ///< 
+               bool      format =false,  ///< Use a formated label?
+               unsigned  gap =2,         ///< betwen the content  and the external limit
+               rectangle r ={}           ///<
+              );
+        place& plc  (){ return plc_inner; }
+        window inner(){ return content; }
+        label& lbl  (){ return titel; }
+    };
+
+}//end namespace nana
+#endif