Don't disable IO buffering at startup

It was never clear to me why we needed this trick, and now
that we rely only on C++ std::getline() and std::cout for
input / output it is even more a mistery what this code does.

So disable it and wait to see if someone screams ;-)

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>