added utils/Roland_Sylvain_gravity/display_g_vector_norm_SPECFEM3D_GLOBE...

..._with_GMT_absolute.sh utils/Roland_Sylvain_gravity/display_g_vector_components_SPECFEM3D_GLOBE_with_GMT_absolute.sh utils/Roland_Sylvain_gravity/display_G_tensor_components_SPECFEM3D_GLOBE_with_GMT_absolute.sh