nanshe/advanced_image_processing.py: In extract_f0, added types in documentation for temporal_smoothing_gaussian_filter_stdev and spatial_smoothing_gaussian_filter_stdev.
nanshe/advanced_image_processing.py: In extract_f0, added documentation for other types.
tests/test_advanced_image_processing.py: Stripped out step argument to extract_f0 from tests as it is no longer used.
tests/test_nanshe_learner.py: Stripped the step argument for extract_f0 as it is no longer used.
nanshe/advanced_image_processing.py: Enforce defaults of wavelet_transform. As these could be changed by the configure file and we do not wish to have them exposed, it is nice to force them to a value so that setting them to another value should result in an error.