Add code to track and calculate total bandwidth when running the test.
Update json field name to be more clear based on feedback from @solidsnack
More granular automation.

Handles custom addresses for the test runner, handles IPv4
Starting to wire in mpstat collection as part of the test execution. The data still needs to be interpreted.
Parse results of `mpstat` command.
Finish adding in cpu metrics reporting for a test.

The following (system) CPU metrics are now reported for each CPU and 'all' CPU:
```
usr/p50
usr/p95
sys/p50
sys/p95
irq/p50
irq/p95
iowait/p50
iowait/p95
```
Remove special handling for 'all'
Silence annoying curl upload progress for json doc.
Update MpStatsCollectorLineHandler to account for a potential additional column named 'gnice'.

Also improved the logging for unhandled lines and the handling for blank lines and the starting header line.
Allow JSON output to be saved.