py_spec minor bugfix

[missing-user]

None checks should be done with is None in python, instead of == None to avoid issues with equality overloads. Passing an RGB color (np.array) to to the plotting functions threw at the None comparison, because numpy arrays need .any() or .all() for comparisons. I also refactored other instances of the same bug across the codebase.

plot_poincare now also ignores points that were unsuccessfully integrated instead of plotting them at [0,0]

[smiet]

Waiting a bit to merge as I am in the process of recovering the SPEC-devel PYPI account to fix the upload to PYPI workflow.