Replace \x08 with \b

[turicas]

I think \b (for backspace) is more legible than \x08 -- this is what the first commit does.
But we don't actually need sys.stdout object since the print function can receive flush and end and we can use carriage return (\r) to remove the entire line (the ' ' * len(status) + '\b' * len(status) "magic" is not needed), then the verbosity of sys.stdout.write/flush are not needed.