do not display output with --results

[Jakub Otwinowski]

Hi,

Thanks for making parallel. Its been of great use to me. I have been
using --results and it works fine, but... I've been running 45 processes
in parallel each with a few hundred MB worth of output, and it all gets
dumped to the terminal as well as disk. Is there a way to suppress the
output to the screen so I can see the --progress ? I noticed that
--files does this, but --results does not.

Thanks,
Jakub