ENH : avoid error in plot_time_frequency_mixed_norm_inverse.py
Merge pull request #450 from joewalter/TF_MxNE_example

ENH : avoid error in plot_time_frequency_mixed_norm_inverse.py
API / ENH: improve readability, drop catch
Merge pull request #451 from dengemann/ica_notebook

API / ENH: improve readability, drop catch