Restructuring into subpackages

preprocessor/preprocessor/output.py

preprocessor/preprocessor/steps/__init__.py

preprocessor/preprocessor/steps/georeference.py

preprocessor/preprocessor/steps/output.py

preprocessor/preprocessor/steps/stack.py

preprocessor/preprocessor/steps/subdataset.py

preprocessor/preprocessor/transfer/__init__.py

preprocessor/preprocessor/transfer/abc.py

preprocessor/preprocessor/transfer/local.py

preprocessor/preprocessor/transfer/swift.py

preprocessor/preprocessor/transfer/util.py

preprocessor/preprocessor/util.py