cPickle.c, load_build():  Taught cPickle how to pick apart
the optional proto 2 slot state.

pickle.py, load_build():  CAUTION:  Noted that cPickle's
load_build and pickle's load_build really don't do the same
things with the state, and didn't before this patch either.
cPickle never tries to do .update(), and has no backoff if
instance.__dict__ can't be retrieved.  There are no tests
that can tell the difference, and part of what cPickle's
load_build() did looked accidental to me, so I don't know
what the true intent is here.

pickletester.py, test_pickle.py:  Got rid of the hack for
exempting cPickle from running some of the proto 2 tests.

dictobject.c, PyDict_Next():  documented intended use.
diff --git a/Lib/test/test_pickle.py b/Lib/test/test_pickle.py
index ac2a596..9cfb9b7 100644
--- a/Lib/test/test_pickle.py
+++ b/Lib/test/test_pickle.py
@@ -5,11 +5,10 @@
 from test import test_support
 
 from test.pickletester import AbstractPickleTests
-from test.pickletester import TempAbstractPickleTests as XXXTemp
 from test.pickletester import AbstractPickleModuleTests
 from test.pickletester import AbstractPersistentPicklerTests
 
-class PickleTests(AbstractPickleTests, AbstractPickleModuleTests, XXXTemp):
+class PickleTests(AbstractPickleTests, AbstractPickleModuleTests):
 
     def dumps(self, arg, proto=0, fast=0):
         # Ignore fast