* Move copyright notice to top and indicate derivation from sets.py and   dictobject.c. * Have frozenset_hash() use entry->hash instead of re-computing each   individual hash with PyObject_Hash(o); * Finalize the dummy entry before a system exit.
* Move copyright notice to top and indicate derivation from sets.py and
  dictobject.c.
* Have frozenset_hash() use entry->hash instead of re-computing each
  individual hash with PyObject_Hash(o);
* Finalize the dummy entry before a system exit.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator