DynamicNodeWalker is our secret weapon in the fight against the Rebel XSLT Alliance
Navigate nodes by calling Up(), Down(), Next() and Previous() on them
Next(1) will jump two items along within the current list, whereas Next() will walk by one within the list
Previous(1) will move two items backwards within the current list
Up() is a special wrapper around .Parent which has an overload .Up(int) to replace @Model.Parent.Parent.Parent... [.Up(2)]
Down() will take you to the first Child item and is equivilent to .Children.First(), use .Down(1) to replace .Children.First().Children
If one of the NodeWalker functions fails to find a node at the requested position, it will return null
