What rules have been used for the current list of codepoints?

[Kenneth Whistler]

Mark suggested:

   - We've been forgetting to remove default-ignorable-code-points, so I
   added an exclusion. It only affects variation selectors.

I concur with that. It was going to be my next suggestion to pare
away. I had neglected to spot them right away because I had
already omitted printing out anything from Plane 14.

--Ken