This module has been deprecated for a while as it's much too trivial to
warrant being its own module, has been incomplete since its inception,
and there's no interest in maintaining, finishing, or expanding it.
Normally, this would be too small to warrant its own module, but smooth
scrolling is one of those things that can tip large swaths of
fence-sitting beginners into Emacs' camp. I can't help but imagine how
many people get their impression that Emacs is "laggy" or "slow" solely
from the way it scrolls.
Don't get me wrong, there *are* good reasons to call Emacs slow, but
startup and scrolling speed are not it, yet they are easily overblown
because it's the first thing you see. I might even consider enabling
this by default, but I'll make that decision later.
Fix: #8335
