[Docutils-develop] image paths

[Alan <ala...@gm...>]

Image paths are now changed from forward slashes to backslashes on Windows.
But that won't work with LaTeX writers, because backslashes start commands.
The LaTeX writers need to retain forward slashes in the image paths.

I've never needed docutils to mess with my paths, and this change is very
problematic.
I recommend returning to the status quo ex ante.

Alan Isaac