Added OpCompressedCache
Stacker: Don't do anything in propagateDirty if the operator isn't finished configuring.
Added OpCachedLabelImage
Renamed opCachedLabelImage.py in preparation for a refactoring.
OpVigraLabelVolume: Allow background value to be specified as a 1-element ndarray, and don't force the dtype to uint8.
OpCachedLabelImage: Refactored labeling portion into its own operator.
- Also, added a test for the background labeling feature.
OpCachedLabelImage: Moved to a separate source file.
roi.py: extendSlice: Make sure that slices are always returned as ints, not floats.
OpCompressedCache: Fixed a typo that caused crash during cleanup.