Away3d and Starling using shared stage3DProxy

[natami]

When Away3D and Starling are sharing a stage3DProxy context, and one wants to dispose() the view3D, the stage3DProxy is also disposed in the view3D, resulting in a null pointer in Starling, as the shared stage3DProxy is now null.

Solution could be to check for:

public function dispose() : void {
if(!shareContext) {
_stage3DProxy.dispose()
} ...
}

[ringodotnl]

Fixed in dev branch see commit af36a58