OK, I misundertood the latest proposoal: to have the option off by default,
but by including in generic a defopt that removes the extra code, rather
than by NOT including a defopt that selected arbitrary sector sizing.

I suppose that's better, but it still seems strange. I would think that
the option should add the feature, not remove it, especially for this case
of an exotic and rarely-if-ever-used feature.

	ross.harvey@computer.org