26902 Initial code review

Created a branch from the very first commit to be able to review the whole code written so far.
This does not mean that a merge should be done after the review is done, this is a "dummy" pull request.
I feel like the message should not be formatted here, but the standard logger error or exception methods should be called with appropriate arguments set ( e.g. exc_info ). It will be than up to registered handlers and formatters to display the message in the most appropriate form.