- Finish event subscription
- Review FocusDurationRegister code, found a lot of naming
  conventions errors and some minor bugs.
- Fix the RecentlyUsed provider
- Test all Relevancy stuff
- Add a WNCK monitor to inform us with window focus
  changes. This module should land into the loggers.

Stuff worth considering:
 - Log package installations/removals/updates.
 - Use Pylint / pyflakes to keep the code clean.
