[ENH] DetachingSubMenus-spfa ( [er] Would cause newbies fits )

[frank at crystal-objects.com]

I've had this change in an image I've used off and on for the past few
days and I've mistakenly detached  menu items on a number of occasions.
This would drive a newbie (and not so newbie) nuts.

If an individual needs this for development purposes he should file it
in to the image where he neeeds it. The only possible way this should be
in the image is if a perference was added to turn it on.