CHANGE-709 - Refactor logging infrastructure (continuation)

CHANGE-709 - Refactor logging infrastructure (continuation from earlier changes)
- fix chicken/egg problem with log initialization
- add explicit logging messages in more places
- relocate log-delete code to logwriter
<a href='#crh-start'></a><a href='#crh-data-
Nevertheless, I've rewritten the tests to no longer explicitly test those methods, but rather to test them indirectly by invoking other methods which in turn invoke the private methods. Of course this creates more duplication of (setup) code in tests and slows tests down, but gets around the issues you were complaining about.