Cleanup for Spheres and PSC (#827)

* Fade fixes
  * Clean up RenderableSphere. Add orientation properties.
  * Sane defaults for Digital Universe
  * Clean up New Horizons related code
  * Add basic scene
  * Add ability to initialize rotation as quaternion and mat3
  * Adapt legacy code to new Renderable interface

modules/space/rendering/simplespheregeometry.cpp

@@ -124,7 +124,7 @@ void SimpleSphereGeometry::createSphere() {
     const glm::vec3 radius = _radius.value();
 
     delete _sphere;
-    _sphere = new PowerScaledSphere(glm::vec4(radius, 0.0), _segments);
+    _sphere = new PowerScaledSphere(radius, _segments);
     _sphere->initialize();
 }