Add insert-height function
Remove benchmarking and expiremental code
Add size field to node struct
Adjust copy-array-node for new node field
Qualify struct name as an array node
Add array-node-length func
Add mutating node funcs, update node constructor to use them and take size explicitly
Update notes
Fix node constructor name, add node element accessor
Remove old funcs, add parent-path constructor
Add initial implementation of persistent array ops
Remove unused gf defs
Add height field to persistent-array
Add todo note
Remove size field from node struct
Pass parameter to ARRAY-NODE-SIZE
Lookup elements in the children array, not the struct
Comment out unused func
Fix func name
Use the right variable name