Proper Cursor Handling Across Different Actors

[Crigges]

Take a look at the following gif:

I just added a VisSplitPane as "first Widget" to another VisSplitPane:

VisSplitPane subPane = new VisSplitPane(new VisTable(), new VisTable(), true);
VisSplitPane superPane = new VisSplitPane(new VisTable(), subPane, false);

You can see that the SplitPaneCursorManager is having trouble to do it's job, and yet I am just using raw VisSplitPanes without any content.

While I think this might be fixable by some workaround, I actually plan to add some custom widgets to the VisSplitPane which require some custom cursor appearance aswell.

So I think some cursor management across all actors is needed.

What are your thoughts about this?