TCAD converter update

A few improvements in the converter. The converter parameter is now parsed via a configuration file (instead of command line arguments). Please, check the readme file. Now it is possible to freely rotate the mesh coordinates by indicating what tcad mesh axis should be on each x y and z coordinate, respectively (such as xyz = y z x). The TCAD mesh reader can create a ROOT file containing the mesh nodes in a TTree. This can be enabled by using the mesh_tree parameter in the configuration file. In addition, in order to help to debug problematic conversions, it is possible to create a 3D screen-shot of the new mesh node, being interpolated, surrounded by the original TCAD mesh nodes with the found neighbors (for a certain radius) highlighted in blue. This screen-shot is stored in a ROOT file as a TCanvas containing a TGraph2D. This is currently implemented only for 3D meshes.