[tex4ht] [bug #394] Support for oolatex on Debian

[Michal Hoftich]

>>
>> I didn't follow (or understand) which path you need to
>> find but kpsewhich -expand-var=$TEXMFDIST gives the main
>> miktex root on my system.
>

Thanks Ulrike, $TEXMFDIST seems to work in Miktex. I've found that I
had broken Miktex installation on a test machine, so it reported wrong
path, but clean reinstall fixed that.

I've updated make4ht with the following mechanism:

1. try to locate tex4ht.jar in path based on $TEXMFROOT, $TEXMFDIST or
environmental variable $TEXMFROOT.
2. if the previous step fails, use kpse.find_file function to find
tex4ht.sty. The /tex/generic/tex4ht/tex4ht.sty part is removed from
the found path and the rest is used to locate tex4ht.jar.

I hope this should cover most cases. I've tested it on TL and Miktex
and it works, but user testing is welcome!

> I think that this is not cross-platform from the command
> line because of the various meanings of special characters,
> in particular, '$'.  In a GNU/Linux command line either the
> '$' needs to be escaped with '\' or the whole first argument
> of kpsewhich needs to be enclosed in ascii single quotes so
> that the '$' is not intercepted by the shell.

I use Lua functions from the Kpse library, so this shouldn't be issue.
The interface can be used in this way:

     texmfdist = kpse.var_value("TEXMFDIST")

Best regards,
Michal