Set minimum and maximum spatial extents for view frustum logic

[markcmiller86]

Is your feature request related to a problem?

We use spatial extents to try to prime the view parameters and view frustum. But, we've invariably run into problems with the spatial extents involved are really, really large or really, really small. The typical result is a funky looking view window with no recognizeable plot in it. The solution is always for the user to manually scale their data by adding their own Transform operator.

Can we just get this right to begin with?

I suspect the view issues are caused by numerical sensitivies in the underlying GL coding. We should just identify what are the sort of extreme values we can work with naturally and then never set spatial extents outside of that range where the view is concerned and either inform the user they should add the Transform operator or, maybe somehow automagically scale the spatial extents.

This came up as a result of some work @nDimensionalSpace was doing with a point mesh consisting of a single point...its spatial extents are zero by definition. We should be able to handle this but don't.