tests: Added @timeLogged to pixel classification labeling tests.
DataSelection: Respond to double-click of an empty table.
OpPixelClassification: Replaced OpBlockedSparseLabelArray with OpBlockedLabelArray
Labeling, PixelClassification: Removed all MaxLabel slots and connections.
LabelingGui uses LabelNames slot to sync label list between images.
OpPixelClassification: Updated for classifier lazyflow changes: Use OpValueCache.fixAtCurrent instead of OpTrainRandomForestBlocked.fixClassifier
PixelClassification: Headless: Unfreeze classifier before executing headless predictions.
tests: PixelClassification: Updated for recent changes to top-level operator (no max label slot)
ProjectManager: Disable gc while loading the project (lots of graph setup, probably faster this way).
logging: config: Added a few logger entries.
PixelClassification: Provide NumClasses output slot, determined by the LabelNames output slot.
PixelClassification: Reconnect the (recently re-added) OpPredictRandomForest.LabelsCount slot.
OpPixelClassification: Set training op MaxLabel slot in sync with LabelNames slot.