Adding a tool that estimates normals over 3D implicit polynomial shapes....

... Statistics, exports, visualisation, perturbation, several estimators are available.

Need DGtal/PR#803


Nice the visualisation, I think that we could then have also a potential export in Obj with the Board3D export of David, I try it but for now I forget that the specific  Display3DFactory::drawOrientedSurfelWithNormal is not implemented in Board3D. I add an issue for future release in DGtal.