Quite a few fixes to make the library and test suite more robust when
cPickle cannot be imported.  This was necessary because my last mass
checkin broke cPickle and I don't feel like debugging it right now;
but it seems a good idea in general not to require cPickle when
pickle.py is also there.  A few unrelated fixes for issues while
debigging various test failures.

setup.py: disable building of cPickle until I've fixed it

Objects/...

  genobject.c: disallow raising string exceptions

Lib/...

  Cookie.py: fix doctest not to fail if cPickle is missing
  ctypes/macholib/dyld.py: fix relative imports
  sqlite3/__init__.py: fix relative import
  xml/dom/__init__.py: fix relative import

Lib/test/...

  regrtest.py: reduce list of skipped items on darwin

  test_generators.py: don't test string exceptions; test throw() errors
  test_traceback.py: don't test string exceptions

  pickletester.py: don't fail if cPickle is missing
  test_datetime.py: don't fail if cPickle is missing
  test_descr.py: don't fail if cPickle is missing (still some other failures)
  test_exceptions.py: don't fail if cPickle is missing
  test_re.py: don't fail if cPickle is missing

  test_array.py: use pickle, not cPickle
  test_bool.py: don't fail if cPickle is missing
  test_deque.py: use pickle, not cPickle
  test_logging.py: use pickle, not cPickle
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index 68c23c2..fe05123 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -25,7 +25,7 @@
 """
 
 import select
-import os, sys, string, struct, types, cPickle, cStringIO
+import os, sys, string, struct, types, pickle, cStringIO
 import socket, tempfile, threading, time
 import logging, logging.handlers, logging.config
 from test.test_support import run_with_locale
@@ -70,7 +70,7 @@
                 raise
 
     def unPickle(self, data):
-        return cPickle.loads(data)
+        return pickle.loads(data)
 
     def handleLogRecord(self, record):
         logname = "logrecv.tcp." + record.name