Issue #6676: Ensure a meaningful exception is raised when attempting
to parse more than one XML document per pyexpat xmlparser instance.
(Original patches by Hirokazu Yamamoto and Amaury Forgeot d'Arc, with
suggested wording by David Gutteridge)
Issue #17654: Ensure IDLE menus are customized properly on OS X for
non-framework builds and for all variants of Tk.