Ospray: Latvol Fix and Camera Optimization

[tarkpate]

This fits with issue #1949, but probably shouldn't close it.

The latvol construction for ospray had 2 problems that I fixed:

• The y position of the origin was not set
• The dimensions needed to be reduced by 1 to calculate spacing

The reason for the spacing change is that there is 1 less segment of space than there are boundaries. For example, a latvol with dimension 5 along an axis would have nodes at [0, 1, 2, 3, 4], but the ranges of spacing would be [0-1, 1-2, 2-3, 3-4], which has 4 segments of space.

The camera data was being recomputed before accruing every frame, so I saved camera object for reuse.

[dcwhite]

QObject::connect: No such slot SCIRun::Gui::OsprayViewerDialog::setWidth(igeomDataTransientnt)
QObject::connect:  (sender name:   'viewerWidthSpinBox_')
QObject::connect:  (receiver name: 'OsprayViewer')

[dcwhite]

Also, I get a crash when OsprayViewer is deleted. Please check that all cleanup is done in the destructor.

[dcwhite]

OK the destructor crash can be fixed with a change in ModuleWidget.cc, around line 363:

isViewScene_(name == "ViewScene") //TODO

remove the check for name == "OsprayViewer". There's some extra code that gets confused now related to window position saving. Please add this to this PR @RubioJr9