RE: option doc strings and Customize tags

["Stephen J. Turnbull" <stephen@xemacs.org>]

Drew Adams writes:

 > That's the abbreviating I suggested. But I'd recommend eliding the terminal
 > chars, not the middle ones.

I think I'd want to see some data about that.  Specifically, I know
several places where there are very-long-prefixed-class-INSTANCE
families, and I'd want to know whether these are "rare".  I suspect
not, I think that's a pretty common practice in naming families of
manifest constants.

OTOH, Customize already generally strips group prefixes.  That might
be enough here, it may not often matter because abbreviation is rare.