could make plotting easier although cpu_util == 100-cpu.idle

Also, simple Argparse argument parsing (--logging)

works.

But some cleanups, etc are still to do..

logs Time, CPU, and NIC to display

- JSON
- CSV header

In order to roughly synchronize with other instances.

Also added some comments.

some ui unifications..

just some todos..

rough first version (rounding issues..)

consistently use Bits/s and display MBits/s

TODO small fix need (speed is Mbit/s ?)

added CPU util

inspired from bwTOP, only network (so far)

rounding (also to KBytes/s)
actually look at bytes/s instead of packets/s

incl. adapted version of "calculate_cpu_times_percent" function from psutil source code