Serializer: Added SerialHdf5BlockSlot
LayerViewerGui: Avoid assert when top-level operator contains non-arraylike slots.
ObjectExtraction: Serializer: Use SerialHdf5BlockSlot for serializing labels.
OpObjectExtraction: Updated name of RegionCenters feature.
OpThresholdTwoLevels: Fixed OpSelectLabels.propagateDirty(), added support for direct hdf5 serialization of output.
Disable all debug loggers.