[XeTeX] How to tell Xetex don't embed some ttf font into pdf

[Arthur Reutenauer]

> And therefore it would be appropriate to write to Adobe and ask them  
> to make in future better, sensible, standards.

  This remark is in my opinion completely unfair.  Adobe has put
incredible efforts into making PDF 1.7 an ISO standard, and PDF was
already very well documented before that.  The TeX world has benefited
from that a lot (and, before, from PostScript, Type 1 fonts, etc.).
Besides, I don't see the benefit for individuals of having PDF published
as an ISO standard, since the ISO documents are ridiculously overpriced
(http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=51502),
while the Adobe technical specifications have been available free of
charge for decades (https://www.adobe.com/devnet/pdf/).

  Anyway, the above is irrelevant for the discussion at hand: we're
discussing a feature that relies on Adobe Reader as a widespread PDF
viewer, not on PDF as a standard.  It's about extending XeTeX's
capabilities, not the PDF specifications (which would only make things
more difficult for third-party viewers). There is a sensible reason to
support the feature (reduce output file size), and there is a (huge)
user community for it.

  Then again, I'm not advocating adding that feature unconditionally,
I'm only asking you to not dismiss the request with a mere "but it's not
standard anyway" and I'm saying it is worth considering.  But of course,
it depends on the implementers.  Jonathan, are you reading us?

	Arthur