Fix listbox for auto_draw+inline_factory+item_proxy::value.

When calling templated append() overload on a shown listbox, auto_draw
caused an early redraw, which issued the inline widget set() member
function before the value() and value_ptr() were actually set.

include/nana/gui/widgets/listbox.hpp

@@ -368,6 +368,9 @@ namespace nana
 					item_proxy iter{ ess_, index_pair(pos_, size() - 1) };
 					if (set_value)
 						iter.value(std::forward<T>(t));
+
+					update();
+
 					return iter;
 				}
 
@@ -441,6 +444,7 @@ namespace nana
 				essence_t*	ess_{nullptr};
 				category_t*	cat_{nullptr};
 				size_type	pos_{0};  ///< Absolute position, not relative to display, and dont change during sort()
+				void update();
 			};
 		
 			struct export_options