Refactor and cleanup

ocr4all_pixel_classifier_frontend/__init__.py

...pixel_classifier_frontend/compute_image_normalizations.py

ocr4all_pixel_classifier_frontend/create_dataset_file.py

ocr4all_pixel_classifier_frontend/evaluate.py

ocr4all_pixel_classifier_frontend/find_segments.py

ocr4all_pixel_classifier_frontend/gen_masks.py

ocr4all_pixel_classifier_frontend/generate_image_map.py

ocr4all_pixel_classifier_frontend/main.py

ocr4all_pixel_classifier_frontend/migrate_model.py

ocr4all_pixel_classifier_frontend/predict.py

ocr4all_pixel_classifier_frontend/scripts/__init__.py

ocr4all_pixel_classifier_frontend/train.py

setup.py