Sol.data.frames.TraverseFrameHierarchy

Sol.data.frames.TraverseFrameHierarchy = function(fn, root, level)
Traverse a frame hierarchy created with Sol.data.frames.SetupFrameHierarchy,
calling fn for each node. Starts at root.
Parameters:
+ fn - The callback function that will be used for every node in the tree.
 It should have the following signature:
 function(node, parentNode, treeLevel)
 ~~ node - the node being examined
 ~~ parentNode - that node's parent
 ~~ level - how far down in the tree this node is
+ root - The node to start traversing at. 
+ level - The node level at the start of the traversal. This will be
 incremented as we go deeper into the tree and is passed to fn
 as one of the parameters.
Note: Requires Sol.data.frames.SetupFrameHierarchy to be run first