[tex4ht] [bug #309] tex4ht does not work with package savetrees

[Karl Berry]

It seems to me that there is a difference between savetrees, which
simply makes no sense in HTML, and tcolorbox, which does.  I don't think
Michal was advocating blanket application of blacklisting packages.

fontspec is another case where it is clear that whatever it does in the
TeX world, it has to do something completely different in the HTML world.
Anyway, fonts are a difficult issue.

As for authors fixing packages to work with tex4ht, does that ever
happen :(?

In any case, a warning and log message about non-inclusion make sense to
me, so the non-inclusion is at least visible, not completely silent.
(Aside from absence of reading the savetrees.sty file ...) -k