Display-Thresholding added in LabelingGUI, depends on ilastik changes
removed function dtype_to_default_normalize
added window_leveling property to Grayscalelayer; thresholdingcontroler now adjusts the threshold automatically when the channel is changed, identification of layer based on window_leveling flag
Merge pull request #140 from ilastik/thresholding

Display-Thresholding added in LabelingGUI, depends on ilastik changes