EPUB2 vs. EPUB3: Making base.dir consistent?

Hi,

thanks to Bob's changes for the EPUB3 stylesheets, the parameter
base.dir makes more sense. Many thanks! :)

I would like to ask if it would be useful to add the same change to the
EPUB2 stylesheets. 

As far as I can see, it would be compatible with the existing
implementation, but would be a huge benefit for stylesheet writers and
developers. I believe, it should be consistent between the two EPUB
implementations.

Opinions, thoughts?

-- 
Gruß/Regards,
    Thomas Schraitle