[tlbuild] tex4ht binary update please

[Karl Berry]

I just made a tiny change to tex4ht.c (in Build/source/texk/tex4htk)
to allow the tex4ht binary to process the updated xdv id byte in xetex
for tl'2016 (i.e., 0.99996).  Without this, htxelatex and the like
simply bail out.

It's certainly not important to update the tex4ht binary on every single
platform, barring user requests, but it would be nice to have the
major ones -- x86_64-linux (Norbert?), *-darwin (Dick), w32 (Akira)?
There is no harm in updating others for those who want to.

The change to the source is below.  There have been numerous and varied
other changes to the source tree since the release, but they should not
affect recompilation.  Of course if you can apply the change to your
existing 2016 source tree, that would be safest.  (I don't feel like
making a branch and asking everyone to use it, that seems like a lot of
extra work for no real gain.)

In any case, nothing but the tex4ht binary is needed or desired.
Everything else will have changed if you compile from the current
sources, but don't commit any other new binaries!  (And if there are
build breakages [not unlikely], that is a separate problem.)

Thanks,
karl

--- tex4ht.c	(revision 41672)
+++ tex4ht.c	(working copy)
@@ -6809,8 +6809,8 @@
     ||
     ((ch != 
 2 
-) && (ch != 
-5
+) && (ch >
+10
 
 ))
   )  bad_dvi;