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-
> It seems better to be called from the constructor.

Calling it from the constructor creates a ton of dependencies for unit-tests. Calling it where needed avoids that problem.