Logging configurable by environment variables
- Configure logging through environment variables.
- Describe how to use it.
- Compile trace logging in by default again. Can still be disabled by a compile switch, to get some more performance.
- Disable most of the logging in tests.
It is market as merge to a non-master branch, but only to hide the commits from review here (they are already being reviewed there).
This is for #9 (closed). That would make logging usable for at least the near future.