example/gui: add notebook demo

There is notebook demo but somehow the workbench didn't show it...

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1813 bbd45198-f89e-11dd-88c7-29a3b14d5316

examples/gui/SConscript

@@ -22,6 +22,7 @@ demo_view_progressbar.c
 demo_view_radiobox.c
 demo_view_listbox.c
 demo_view_slider.c
+demo_view_notebook.c
 demo_view_combobox.c
 demo_view_listctrl.c
 demo_view_menu.c

examples/gui/demo_workbench.c

@@ -83,6 +83,7 @@ static void workbench_entry(void* parameter)
 	demo_view_listctrl(workbench);
 	demo_view_combobox(workbench);
 	demo_view_slider(workbench);
+	demo_view_notebook(workbench);
 	demo_view_mywidget(workbench);
 #if defined(RTGUI_USING_DFS_FILERW) || defined(RTGUI_USING_STDIO_FILERW)
 	demo_view_image(workbench);