bug#28834: 25.1; dired-do-copy: allow to copy into a nonexistent directory

[Drew Adams]

Thanks for working on this, Tino.

I haven't looked at it in detail.

1. Maybe name the function `dired-maybe-create-dirs'
   (and I don't see why its name should suggest that
   it is internal).

2. I think this should use `%s', no?

  (format "Create destination dir '%s'? " dir))

(I'm also surprised that we apparently now use
'...' instead of `...' in News, but whatever...)