DataSelection: Serializer: Removed all trace logging.
opThresholdTwoLevels.OpSelectLabels: Optimize for memory usage, not parallel computation.
Added memory usage debug logging statements.
workflows: Auto-import all known workflows on 'import workflows'
logging: Added config entries for data selection and two-level thresholding.
OpObjectExtraction: Fixed an off-by-one error in the calculation of object bounding-boxes.
synapse_pipeline: blockwise workflow: debug code.