Revisit purpose of utilities, plus test and document

[dbuscombe-usgs]

All utilities need better descriptions and testing. I would like to explore each of the utilities in turn, removing and editing where necessary. This should be done before Nov 10.

Some utilities are probably in a majority of workflows:

• batch_resize_images.py

• gen_images_and_labels.py

Others are 'advanced' and not in a typical doodler workflow - still useful, but their usage needs to be better explained/emphasized

• gen_remapped_images_and_labels.py

• make_classified_tiles_from_images_and_labels.py

• plot_label_generation.py

• transfer_doodles_to_new_image.py

Some utilities may now be redundant, their outputs already provided by other utilities:

• gen_overlays_from_images_and_labels.py

• gen_npz_4gym.py

• viz_npz.py

[dbuscombe-usgs]

I verified that the following can be removed (I have done so in my branch bugfix)

• gen_npz_4gym.py
• viz_npz.py
• transfer_doodles_to_new_image.py

I tested the following and advocate keeping:

• batch_resize_images.py
• gen_images_and_labels.py
• gen_overlays_from_images_and_labels.py
• make_classified_tiles_from_images_and_labels.py

I fixed the following (in my branch bugfix) and advocate keeping:

• plot_label_generation.py
• gen_remapped_images_and_labels.py

For the latter, I added an example config file for remapping from classes to 'superclasses'