* refactored registry operations some. subkey lists and

* refactored registry operations some.  subkey lists and
  registry values are now passed around in containers
  (REGSUBKEY_CTR & REGVAL_CTR) which each possess a TALLOC_CTX.

* removed subkey_specific_fn() from REGISTRY_OPS.  Is implemented
  in the form of a wrapper

* temporarily broke the printing registry ops.

* implemented inheritence for the data_p of nodes in a SORTED_TREE

* All REGISTRY_KEY instances now store a valid REGISTRY_HOOK since
  the default REGOSTRY_OPS structure is stored in the root of the
  cache_tree.

* Probably some other change I forgot....  T
(This used to be commit e7b55e8f017e638342d9c8c1a9259000745a0298)