[Python-3000] New io system and binary data

[Bill Janssen]

> Also, if there are other places in the
> > documentation
> > where it seems to imply that the distinction between text and binary modes is
> > meaningless on Unix systems, drop me a note and I'll have a look.

That's certainly the prescribed behavior for the C stdio streams on
POSIX-compliant systems.  I think a lot of the original design of the
Python I/O system was based on that C stdio system, including names
like stdin, stdout, and stderr.

Now that we've moved away from the C stdio model, and the distinction
between text and binary streams is meaningful even on POSIX systems,
perhaps we should also change those names to reflect that difference
from C.  Given that Py3K is a once-in-a-decade chance to break
backwards compatibility, and all.  Perhaps something like
sys.io.input, sys.io.output, sys.io.err, or something similar.

Bill