[docbook-css] Different image resources for HTML & FO output

[martin.gautier@myrnham.co.uk]

>> I'm not sure that the possible values for 'role' are well-defined 
enough to blacklist all those that don't apply.

In general I would agree. However do recall seeing comments in Bob 
Stayton's DocBook XSL book regarding the built-in support of "fo" and 
"html" for the specific use of <imageobject>.

>> where the browser tries to load every <imageobject>
I think specific javascript will always be a superior (technically) 
solution however, I agree that you'll probably want to avoid the overhead 
of maintaining large amounts of code. If people want an accurate 
representation in their borwser then I guess they can always run their XML 
through the HTML XSL stylesheets ;o)

Mart