PyInterpreter: fx Python memory management regarding new and borrowed references; improve error messaging
The crash during importing data via Python Fabio package is fixed. The reason was an incorrect memory management of Python 'borrowed' references. The whole PyInterpreter
code is checked again and all borrowed references are marked with a comment.
The error messaging and Python traceback acquisition is corrected and improved; see an example below
Resolve issues #1070 (closed), #1063 (closed)