[dev-context] /AF key for attachments (in PDF/A-3)

Hi Hans, attachments in PDF/A-3 need to be related (as an array) to the document with the /AF key. I already reported this and I think that the most sensible value is to relate them to the document. That would mean to include the /AF key in the /Catalog dictionary. I think this would be the easiest way to implement and to use it. Many thanks for your help, Pablo -- http://www.ousia.tk