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

[Karl Berry]

Hi Michal,

    is updated usepackage.4ht:

Fantastic.  I'm surprised Eitan did not create a mechanism like this.

Anyway, can you commit the lit changes for the new usepackage or send
them to me, if nothing more is pending for it?  Thanks!! -k