Completed Action A-632-01

ACTION A-632-01: Andy to contact Jim to make change to the hierarchy 
diagrams in both XDM and F+O. See bug 29403

Rather than push this onto Jim, I converted the diagram from Visio format 
to SVG and made the change.

https://www.w3.org/XML/Group/qtspecs/specifications/xpath-datamodel-31/html/Overview.html#types-hierarchy
https://www.w3.org/XML/Group/qtspecs/specifications/xpath-functions-31/html/Overview.html#datatypes

Thanks,
- Andy