bug#38392: zap-up-to-char should appear in "Deletion and Killing" Emacs info section and "Command Index"

[Drew Adams <drew.adams@oracle.com>]

> I suppose you’re saying that exactly two ‘inclusivities’ suffice: ‘up to/until’ and 'through' in your case, which makes complete sense.

I wasn't speaking to what might suffice.  I was just
pointing out that we use `up-to' for zapping and `until' for searching - and we mean the same thing by them.  And I mentioned `through' as a possible name for including the final char. 

> I have found that both 'up to' and 'until' are still ambiguous, for instance when trying to agree on a date with someone. This ambiguity might carry over to the Emacs world, where a user might not know that there is another distinct inclusivity called 'through'. 'up to' and 'until' can mean either 'inclusive' or 'exclusive', this seemingly depending on the phase of the Moon. I still use the words 'inclusive' and 'exclusive' to confirm. I hope that at least programmers don't find that silly. Of course, there is an existing precedent of 'up to', 'until', 'through' and 'to'.

Yes, the terms are ambiguous.  If we use consistent
names and the doc is clear then I don't think there's
a problem in practice.  But yes, in conversation,
and particularly with dates/times, people can need
to discuss a bit to be sure to be on the same page.

> Regardless of the naming, wouldn’t an inclusivity modifier over the set of two inclusivities be a nice thing to have?

No idea.  Modifier where?  Here we're talking about
function names.  I don't think we need to or should
add such a thing to the names.