VRayStereoscopic helper support for Vantage.

[AndyMurdock]

VRayStereoscopic helper support for Vantage.
I wish to have support for the 3dsmax VRayStereoscopic helper in Vantage. The most important params being Animated Eye Distance, Top / Bottom output layout.
I'm hoping to use Vantage as a fast renderer for 360VR projects.

[npg]

Top/Bottom output was added in 1.5.0