Per Last Call feedback, removed icons for presence states; redefined the icon field to use media element per XEP-0221.
Upon receiving the disco#info request, the software replies and includes extended information in a data form (&xep0004;), where the icon is communicated using the format defined in &xep0221;.
The fields have the following meaning:
Thanks to Joe Hildebrand for his comments.
+Thanks to Dave Cridland, Olivier Goffart, Joe Hildebrand, Etan Reisner, Remko Tronçon, and Jiří Zárevúcký for their comments.