kconfig/lxdialog: support resize

In all dialogs now properly catch KEY_RESIZE and take proper action.
In mconf try to behave sensibly when a dialog routine returns
-ERRDISPLAYTOOSMALL.

The original check for a screnn size of 80x19 is kept for now.
It may make sense to remove it later, but thats anyway what
much text is adjusted for.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/kconfig/lxdialog/util.c

@@ -509,6 +509,12 @@ int on_key_esc(WINDOW *win)
 	return -1;
 }
 
+/* redraw screen in new size */
+int on_key_resize(void)
+{
+	dialog_clear();
+	return KEY_RESIZE;
+}
 
 struct dialog_list *item_cur;
 struct dialog_list item_nil;