Offline stylesheets create an absolute URI based on creator's environment

The problem prevents the generated relative version of the HTML file from running on other machines. This isn't a problem for the versions with absolute web-based URIs.

There are invocation parameters that can be overwritten, but it would be more flexible for the authored document to indicate the offline directory in which required files are found.

Implement a processing instruction that conveys the base URI of the installation directory and then de-reference the files from that base URI.