Inconsistent use of messaging

[schaefi]

I found several places in the code where logging. is mixed with print and the print statements are also mixed with printing to the default stdout channel or to the stderr channel. I don't see a good reason why the messaging of the tooling is mixed up that way.

I think we should change this to use the python logging facility exclusively and get rid of any extra print statements. If there is need to be to handle specific messages differently it can be done through the logging facility too