Fix SMESH_Mesh_i::CheckGeomGroupModif()
52731: Exception at export of SEG3 groups
Fix BUGs concerning Export:
1) Exception at export of the SEG3 group as a separate object.
2) Many formats available in the pop-up menu when several objects selected while only MED and CGNS formats support several meshes in one file.
3) Export of the mesh and its group to the same file results of storage of the group only. Object names are not kept.
1) Fix common WIN32 compilation errors.
2) Replace WNT deprecated macro definition by the WIN32.
3) Remove unnecessary test executables.
4) Make MEFISTO2D algorithm optional: try to determine f2c generator and generate C code from Fortran, otherwise MEFISTO2D is unavailable.
