even if it isn't. Changes:
- set the global flag Py_InteractiveFlag when -i is given
- call Py_FdIsInteractive() instead of isatty()
- make stdin unbuffered, too, when using -u
- make stdin and stdout line buffered, when stdin is interactive and not -u
Note that setting the environment variable PYTHONINSPECT does not have
these extra effects of -i. (Should it?)
Unlike Lee's changes, I don't set change the prompt to go to stderr
when -i is given.
Guido van Rossum