headless: shell: If the project file doesn't specify a workflow, assume PixelClassification
DataSelection: Support new cmdline arg --preconvert_stacks
Pixel classification: Allow batch inputs to omit time axis, even if it was present in training.
PixelClassification: If the project file is an old one that didn't save the label names/colors, create default ones.
Pixel Classification: flush stdout periodically to show batch mode progress.
Pixel Classification: When providing default label names during deserialization, make sure the classifier remains clean.
docs: Changed version.