xorg 1.18 released

[Tom Horsley]

> You should probably use https://www.changedetection.com and monitor
> http://www.nvidia.com/object/unix.html for changes to see when they release a new driver. 
> And then you can bug the folks at rpmfusion.

Ah-HA! A 352.63 driver just showed up on the nvidia site with this
as one of the items added:

   Added support for X.Org xserver ABI 20 (xorg-server 1.18).

So we just need rpmfusion to catch up now :-).