[InteractiveSegmentation] Segmentation doesn't show up if the following happens

[dboun]

• Load 3 images
• Click the "+" button in InteractiveSegmentation to create a seeds image
• The data manager will have: "Seeds", "Image1", "Image2", "Image3" in order.
• Drag "Image3" up so that the order becomes: "Seeds", "Image3", "Image1", "Image2"
• Draw some seeds for 2 colors on the "Seeds" image
• Click run on InteractiveSegmentation
• When the segmentation is produced and shows up in the data manager, it doesn't show up in the render windows.

Dragging the "Seeds" image to the top seems to mitigate the issue, but regardless it should be fixed.

I think the solution would be something like calling force render window update or something, when the segmentation is produced

[dboun]

Some extra realizations:

• Apparently it is just that "Image3" is covering it, meaning that it's like Image3 is above segmentation in the "stack".
• That's probably an MITK bug sadly, because the order should be what the data manager says and it's not. To test that it's just Image3 covering it simply click on the checkbox of Image3 in the data manager.
• Building on recent MITK code doesn't help.
• Calling mitk::RenderingManager::GetInstance()->RequestUpdateAll(); doesn't help.

There should be some way to work around this bug, though.

[dboun]

This was fixed in PR #109