new debug / logging architecture

Hi Holger,

I'm happy with the new architecture. During testing I made a couple of bug fixes, which I applied to the new 'new-debug-arch' branch in the root directory of the git branch namespace. (i.e. not prefixed with holger/).

It would be great if you could finish this work so we can benefit of it before the congress.

I'll probably merge some initial parts already now (at least the new macro definitions) to start using log levels in the actual code - even if it doesn't get used yet.

Regards, Harald