ANSI Color coding for traceback display

Currently, errors are displayed in plain white instead of having their proper ANSI color coding as sent by the kernel.

Ideally error tracebacks should be color coded.

This might help:
https://pygments.org/docs/lexers/#lexers-for-python-and-related-languages
https://github.com/marcus-oscarsson/pyqtconsole