Segmentations: lice view drawings should be unrelated to 3D view drawings

[Zach Pearson]

Currently the slice views are not independently textured rectangles, they are

This has several drawbacks:

• The math for manipulating the slices is needlessly complex
• The timing of flashing the slices has to be carefully managed
• Errors in the slice views cause the orthoplanes to be superimposed on the 3D isosurface
• Changing the image style of the 3D view can potentially make the slice views go blank

Among many other drawbacks.

The 2D views should be their own textured rectangles.