It would be nice if there was a way to specify the "images" URL on
the command line and/or an option to tell it to generate the images.
Also it would be nice if there was an option to tell it not to
generate either the packages.html, and to check for the existance of
the API_users_guide.html file in either the current directory or
the location specified by the -d option before adding the link to
packages.html.