add material pointer

Слиты nikitronn запросил слияние sv_obj_helper_materials в master

Created by: zeffii

remaining issue is PointerProperty for materials in sv_obj_helper

  • sv_obj_helper material now pointer.
  • bmesh viewer done
  • viz\viewer_curves.py:
  • viz\viewer_metaball.py:
  • viz\viewer_nurbs_curve.py:
  • viz\viewer_nurbs_surface.py:
  • viz\viewer_polyline.py:
  • viz\viewer_skin.py:
  • viz\viewer_typography.py: