Menu entries are often also available in toolbars or other widgets. And
sometimes, we want to enable or disable a given action, and this means having to
update everywhere this action is allowed.
This module helps managing actions in a Tk GUI: just create a new object,
associate some widgets and bindings with add_widget() and then de/activate the
whole action at once with enable() or disable().
WWW: http://search.cpan.org/dist/Tk-Action/
