[tex-live] XeTeX on Mac

[Richard Koch]

Folks,

There was a final glitch in XeTeX Mac font support. The patched versions
didn’t pass tests on the older platforms used to build TeX Live.
Jiang Jiang fixed that problem last night.

I have just submitted new Mac binaries with these patched versions,
and will make new beta versions of BasicTeX-2015 and MacTeX-2015
tomorrow. If you already have older versions of these, TLU should update
to the new binaries sometime tomorrow.

Mac fonts have many variants, and in some cases the patched versions cannot
access all the variants. I think this problem is being addressed. 

Many thanks to Khaled and to Jiang Jiang for very hard work on these
problems. Mac users own them a debt of gratitude.

Dick Koch