Flag to avoid colored output

check_configs.py actually prints only in colore output format. It helps
reading from a terminal, but if redirected to a file, it may be annoying.

So introduce two different modes:
- automatically disable color mode if redirected to a file
- add "--no-color" to noise_parse in case a no colored output is preferred
also for the terminal output.

Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>