0020889: EDF 1433 SMESH: SplitHexaToTetra: add the 24 tetras mode

0020889: EDF 1433 SMESH: SplitHexaToTetra: add the 24 tetras mode

void SMESH_MeshEditor_i::SplitVolumesIntoTetra (SMESH::SMESH_IDSource_ptr elems,
                                                CORBA::Short              methodFlags)
  throw (SALOME::SALOME_Exception)
{
  Unexpect aCatch(SALOME_SalomeException);

+  initData();