libxfce4ui vs. libxfce4gui: wha'?

[Conrad J. Sabatier]

I just noticed the announcement for libxfce4ui version 4.9.0 and it got
me wondering about something.

In the FreeBSD ports collection, we have a libxfce4gui package (note
the "g" up in there), but no libxfce4ui.  Are we missing something that
we should be available here?

Could anyone please explain the difference between these two packages,
and possibly why one of them is non-existent in the FreeBSD ports
collection?

Could this be the reason why I have no "Arrange icons" item on my
desktop menu?  Seems I used to have such an item, but after some port
upgrades, it just "went away", and I've been unable to resurrect it.

Thanks for any clues on this!

-- 
Conrad J. Sabatier
conrads at cox.net