Move the Place comparator to an init file to have .comparing and not .comparing.comparing

...rective/example/processing/contrast_weighted_nearness.pdf

...rective/example/processing/contrast_weighted_nearness.png

...directive/example/processing/michelson_contrast.hires.png

.../plot_directive/example/processing/michelson_contrast.pdf

.../plot_directive/example/processing/michelson_contrast.png

doc/build/plot_directive/example/processing/scene.hires.png

doc/build/plot_directive/example/processing/scene.pdf

doc/build/plot_directive/example/processing/scene.png

...build/plot_directive/example/processing/skyline.hires.png

doc/build/plot_directive/example/processing/skyline.pdf

doc/build/plot_directive/example/processing/skyline.png

doc/source/example/database/load_image_posorient.py

doc/source/example/database/load_image_rowid.py

doc/source/example/processing/apcv.py

doc/source/example/processing/contrast_weighted_nearness.py

doc/source/example/processing/michelson_contrast.py

doc/source/example/processing/pcv.py

doc/source/example/processing/scene.py

doc/source/example/processing/skyline.py

src/comparing/__init__.py