IBM-DM-010: Document-uri property

Data Model Section 6.1.3 (Document Nodes--Construction from an Infoset): 
This section specifies how three of the four properties of a document node 
are derived from an infoset. It should also mention the fourth property, 
"document-uri", and state that it is derived from the absolute URI of the 
resource from which the document node was constructed, as described under 
"Accessors".