style: Don't override the user's system settings by hard-coding widget background colors.
SplitBodyCarving: Don't show irrelevant layers from the carving base class.
SplitBodyCarving: Changed annotation crosshair color to pink.
Carving: When writing seeds, shrink roi to bounding box of all seeds instead of writing (potentially) the whole volume.
OpCarving: Don't use cylemon IndexAccessor to set 0-values, since it has no effect (and is slow).