Prepare plugins/python_shell/ipython_view.py for update.
Fix interactive shell plugin to work with current IPython versions.

Achieved by updating plugins/python_shell/ipython_view.py
(which was taken from the Accerciser project)
to the commit before Accerciser's Python3 migration [1],
reverting their previous PyGI migration [2].

[1] https://git.gnome.org/browse/accerciser/commit/?id=b9bb2f48eebbf9f21ca633b6ecd6a58d6befe04a
[2] https://git.gnome.org/browse/accerciser/commit/?id=48b8c06d598f84943ab7a0af1259408b7409484d
Additional fix for plugins/python_shell/ipython_view.py.