Deprecate the old APIs that used to close over the
metadata about valid node rotations.  Now expose
this data in the node definition, and use a generic
non-closure function to handle the callback.

nodedef.spindata contains:

qty = number of allowed rotations total
cycle = table keyed on current param2 and valued with
  next param2 for next rotation
equiv = table keyed by each possible param2 (24 keys)
  and valued with canonical equivalent for that param2