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'
PixelClassification: Workflow: In batch flow, use OpSelectSubslot to obtain a dataset for shape constraint checking.
Merge pull request #437 from lfiaschi/master

Counting integrate into master
PixelClassification: Show segmentation layer over prediction layer.
Carving: Input layer: direct=True
DataSelection: Don't auto-import gui classes when the applet is imported. (Support headless scripts.)
LayerViewerApplet: Don't auto-import the gui module, since headless scripts may not want it.
Don't auto-include any applet guis, for qt-less headless testing.
ilastik.py: Don't import Qt in headless mode.
Carving: More fixes for headless support.
ilastik.py: Fix an error message about invalid parameters.
DataSelection: Reverted a widget name to keep the recorded test cases passing.
DataSelection: If the user selects a dataset that isn't valid for his workflow, automatically open the dataset property editor.
Resolves #433
OpThresholdTwoLevels: Output cache blockshape is only 1 pixel wide in the time dimension.
Fixes the second part of issue #416