Hierarchy Extensions for Atom

Myself and Nikunj have revised our I-D for expressing hierarchical relationships in Atom Documents. We’ve reduced the scope of the document to focus on just hierarchical navigation. Meta-Publishing for Atompub Collections has been removed and recommendations on how to discover Atompub Collections have been moved to a new BCP (Best Current Practice) Draft. The link relation names have been changed to better harmonise with existing IANA link registrations.