fix Region.set_faces()
fix Region.set_faces()

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