py3: use socket.makefile() instead of dropped smtplib.SSLFakeFile
The latter (undocumented internal) class got removed in Python 3.3. Use
socket.makefile() as suggested:
https://docs.python.org/3/whatsnew/3.3.html#porting-python-code
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)