In core FormFactorTruncatedSphere got recently additional parameter in constructor. It allows to define spheres truncated from both top and bottom.
* Implement the same in GUI
* Think of better parametrization in Core.
> Current one FormFactorTruncatedSphere(double radius, double height, double dh=0.0) to my opinion is confusing.
* Update user manual.
* Same for FormFactorTruncatedSpheroid