update SurfaceField for no element groups
update SurfaceField for no element groups

- update ._check_region(), ._setup_geometry(), ._setup_approximations(),
  .setup_extra_data(), ._init_econn(), ._setup_vertex_dofs(),
  ._setup_bubble_dofs(), .get_econn(), .average_qp_to_vertices()

sfepy/sfepy,BubuLK/sfepy,BubuLK/sfepy,RexFuzzle/sfepy,rc/sfepy,rc/sfepy,vlukes/sfepy,rc/sfepy,lokik/sfepy,RexFuzzle/sfepy,lokik/sfepy,lokik/sfepy,vlukes/sfepy,BubuLK/sfepy,sfepy/sfepy,RexFuzzle/sfepy,vlukes/sfepy,sfepy/sfepy,RexFuzzle/sfepy,lokik/sfepy