nanshe/advanced_image_processing.py: In remove_zeroed_lines, respect input data's dtype for result.
nanshe/simple_image_processing.py: In zeroed_mean_images, respect input_array dtype for output_array.
nanshe/advanced_image_processing.py: Removed lingering spams import.
spams_sandbox/spams_sandbox.py: Added comment for spams import.
nanshe/advanced_image_processing.py: Added conversion to double in generate_dictionary and conversion back to the original provided type.