OpDataSelection: When applying user-specified dataset metadata, don't overwrite existing fields with 'None'.
SplitBodyCarving: Refactored parsing function in preparation to move it into the operator.
SplitBodyCarving: Moved annotation parsing code to the operator, so it can be used without the gui.
OpSplitBodyCarving: Moved annotation parsing operator into its own file.
HeadlessShell: Import known workflow modules before loading the project.
SplitBodyCarving: Supervoxel Export: Added command-line interface for producing supervoxelized bodies.
Merge branch 'split-body-preprocessing'