From SF patch #852334.

Should all the commented out code be removed?

Replaces calls to socket.send() (which isn't guaranteed to send all data)
with the new socket.sendall() method.

instead of possibly twice by using a sequence of types to check for.
Add a message to the ValueError that can be raised.

for zone hours. Fixes #499169.

checking in changes.  The test suite requires consistent use of spaces
and tabs.)

Pass binary mode to makefile().

+ test_quopri.py relied on significant trailing spaces.  Fixed.
+ test_dircache.py (still) doesn't work on Windows (directory mtime on
  Windows doesn't work like it does on Unix).