Toolbar widget improvement.

This patch has 2 new features:

1- new option at constructor to enable creation of detached toolbar from
his parent, this enable the use of toolbar anywhere and the size can be
controlled by a layout manager.

2- add a new option in order to enable to place buttons at right part,
the widget has a new method go_right() after calling it, every new
button is right aligned.

Both changes don't break compatibility with old code.

include/nana/gui/widgets/toolbar.hpp

@@ -92,6 +92,13 @@ namespace nana
 		bool enable(size_type index) const;
 		void enable(size_type index, bool enable_state);
 		void scale(unsigned s);   ///< Sets the scale of control button.
+
+		void go_right();
+
+		bool detached() { return detached_; };
+
+	private:
+		bool   detached_;
 	};
 }//end namespace nana
 #endif