Make celery.five importable from outside. Closes #1968

celery/__init__.py

@@ -144,7 +144,7 @@ old_module, new_module = recreate_module(  # pragma: no cover
     __package__='celery', __file__=__file__,
     __path__=__path__, __doc__=__doc__, __version__=__version__,
     __author__=__author__, __contact__=__contact__,
-    __homepage__=__homepage__, __docformat__=__docformat__,
+    __homepage__=__homepage__, __docformat__=__docformat__, five=five,
     VERSION=VERSION, SERIES=SERIES, VERSION_BANNER=VERSION_BANNER,
     maybe_patch_concurrency=maybe_patch_concurrency,
     _find_option_with_arg=_find_option_with_arg,