When sock file close, underlying socket not closed
When sock file close, underlying socket not closed

It appears that in Python 3.4, closing a socket file doesn't close the
underlying socket. I'm not sure if this is a bug or not, but we now
close the underlying socket after the file is closed.

realazthat/pg8000,tlocke/pg8000,kaniini/pg8000,realazthat/pg8000,kaniini/pg8000