PEP8 work, revert some overly strict PEP8

nifty4/__init__.py

nifty4/library/critical_power_curvature.py

nifty4/library/critical_power_energy.py

nifty4/library/log_normal_wiener_filter_curvature.py

nifty4/library/log_normal_wiener_filter_energy.py

nifty4/library/noise_energy.py

nifty4/library/nonlinear_power_curvature.py

nifty4/library/response_operators.py

nifty4/library/wiener_filter_curvature.py

nifty4/library/wiener_filter_energy.py

nifty4/operators/scaling_operator.py

nifty4/plotting/plot.py

nifty4/sugar.py

test/test_energies/test_map.py

test/test_energies/test_power.py

test/test_minimization/test_minimizers.py

test/test_operators/test_adjoint.py

test/test_operators/test_fft_operator.py