COM Dialog: isosurface enables isovalue/opacity
COM Dialog: isosurface enables isovalue/opacity

In the color opacity map editor, only enable isovalue/opacity
spin boxes when the isosurface is being shown.

This clarifies that they are only used for the isosurface, and
not the volume rendering.

Signed-off-by: Patrick Avery <9998cd7370de5e06514e1c73829a1fbd24ae8b10@buffalo.edu>

ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,OpenChemistry/avogadrolibs