Jens' numerics is merged and modified for the new topology

src/ppm_hamjac_ext_step_3d.f

src/ppm_hamjac_reinit_2d.f

src/ppm_hamjac_reinit_3d.f

src/ppm_hamjac_reinit_loc_3d.f

src/ppm_hamjac_reinit_loc_step_3d.f

src/ppm_hamjac_reinit_ref_3d.f

src/ppm_hamjac_reinit_russo_3d.f

src/ppm_hamjac_reinit_russo_step_3d.f

src/ppm_hamjac_reinit_step_2d.f

src/ppm_hamjac_reinit_step_3d.f

src/ppm_hamjac_reinit_step_ref_3d.f

src/ppm_mg_alloc_field.f

src/ppm_mg_finalize.f

src/ppm_mg_init.f

src/ppm_mg_res_coarse.f

src/ppm_mg_res_fine.f

src/ppm_mg_restrict.f

src/ppm_mg_smooth_coarse.f

src/ppm_mg_smooth_fine.f

src/ppm_mg_solv.f