@JensTimmerman had a good explanation why it should be stderr by default, as it was before this patch, so I left it like that.

I believe it was that when logging to screen, you don't want log messages to intervene with the output of the program, so you can pipe the useful (non-log) stuff to other commands, e.g. `mystuff.py | awk 'smart stuff'`. 

For EasyBuild, there's not really any output of value that you could use, so it was spitting out logs to stdout with `-l`, and should keep doing that.

Using stderr in fancylogger by default seems reasonable to me.