App: Add INFO-level logging to track usage
App: Add INFO-level logging to track usage

We want to know whether wm-metrics is used!

- Setup a new logging handler which writes in a rotating usage.log
file all the INFO level events.
- Fire a INFO logging event for the tools submit event

Commonists/wm_metrics,Commonists/wm_metrics,Commonists/wm_metrics,danmichaelo/wm_metrics,danmichaelo/wm_metrics,Commonists/wm_metrics,danmichaelo/wm_metrics,danmichaelo/wm_metrics