Pipeline python logging

Recreating @kenneth.maguire's MR !99 (merged). The first commit of this MR is his code.

Personally, I would recommend using a LOGLEVEL environment variable like this instead of a DEBUG variable. But if you actually intend to use the DEBUG variable for other reasons, feel free to switch back to that, you can drop the second commit mostly then. Please do not use an import from distutils to test a boolean though.

I removed the changes from vat_import.py because it's not our code, it came from the VAT team.

TODO:

• Test this