Multi thread detection

[ClementCaporal]

Should close #67

I propose to use concurrent.futures.ThreadPoolExecutor along with the already existing cfg.SYSTEM.NUM_WORKERS to speed up the process of detection.

On my setup for 5.88 GB:

• 1 worker: >12 minutes 35 seconds
• 30 workers: 1 minutes 20 seconds

@danifranco Can you double check if the new documentation for cfg.SYSTEM.NUM_WORKERS is not too vague now?

[danifranco]

Wow, super useful feature Clement, thanks a lot. SYSTEM.NUM_WORKERS as you changed I think it's good, so don't worry. I'm merging this code now!