[XeTeX] xelatex, hyperref, and new TeXLive

[maxwell]

With the help of David Carlisle and Herbert Schulz, I've found part of 
the problem.  For some reason, in the (our?) 2016 version, kpsewhich 
points to this hyperref.cfg file:
    ...texlive/2016/texmf-dist/doc/latex/listings-ext/hyperref.cfg
This .cfg file contains a \hypersetup{...} command that specifies 
'ps2pdf'.  Changing that to 'xetex' fixes the problem, at least for 
xelatex (I'm not sure what would happen with other flavors of latex).  
(Update: removing the line entirely, so it specifies neither xetex nor 
ps2pdf, works too, and presumably won't cause trouble for other 
latices.)

But:
1) Why does kpsewhich find that file, instead of this one:
    ...texlive/2016/texmf-dist/tex/latex/latexconfig/hyperref.cfg
    which does not have any \hypersetup{} command, and which would
    presumably not cause the same problem?
2) Why did this change from 2015 to 2016?  We did a pretty vanilla
    install, I think the only non-default choice we made was to use
    'letter' instead of 'a4'.
3) Is this a bug? (meaning should I report it?)

    Mike Maxwell