start using CMesh internally in Mesh to store mesh data, no element groups
start using CMesh internally in Mesh to store mesh data, no element groups

- update Mesh._set_data(), ._set_shape_info()

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