[dev-context] proposal for attachments (not restricted to PDF/A)

Hans, I think it would be great to add to all attachments (whether the file is PDF/A or not), the following information in /EmbeddedFile, /Params dictionary (as explained table 46 from page 104 from the PDF spec [https://www.adobe.com/content/dam/acom/en/devnet/pdf/PDF32000_2008.pdf#named...]), the following entries: - /Size - /ModDate - /Subtype with MIME (as already reported). Many thanks for your help, Pablo -- http://www.ousia.tk