Logging

This is a stub.

This file should explain how information is logged (results of all error checks, possibility of adding debugging levels…). I assume we will use Python’s intrinsic logging module (already started, but I think only for writing to screen). Could take example from ppol, where I think I do fairly careful, multi-leel logging. Have to be careful to specify how to setup logging in each command-line program (I assume there will be a standard, automatic level and then each one can activate a more active debugging)