Render ellipsoid primitives in the closest frustum that contains it and clamp the depth so it is not clipped by the near and far planes.
Merge branch 'master' into ellipsoidPrimitive
Merge remote-tracking branch 'origin/master' into ellipsoidPrimitive
Doc and name tweaks
Add test for executeInClosestFrustum.
Merge pull request #468 from AnalyticalGraphicsInc/ellipsoidPrimitive

Ellipsoid Primitive clipping