Here is the best I can do for you. I was able to track down a Google cache of an AddOn called CleanUI that used to be on curseforge. Here is the Google cache link:
http://webcache.googleusercontent.co...&ct=clnk&gl=us
The links on the page go to 404 errors, but the author Nirriti is still active. If you click on Nirriti's profile, you will find that there is apparently a new AddOn that replaced CleanUI. The new AddOn is called Masque: CleanUI.
http://wow.curseforge.com/profiles/Nirriti/
http://mods.curse.com/addons/wow/buttonfacade-cleanui
Looks like you need an AddOn called Masque for this to work. I'm guessing the Legion changes will break CleanUI to the point where the author didn't want to bother with it, and found a way to get the effect they want from Masque and their plugin for it.
- - - Updated - - -
Ok. Here you go. I managed to dig up the download link for the last version 6.2.2 using the Internet Wayback Machine. Even though the Curse pages are dead, this link still seems to work, but get it fast before it disappears. Also, back it up on a USB key or something to save it for the future. Maybe you can contact Nirriti to ask why the AddOn was removed.
https://web.archive.org/web/20150907...cleanui/896386