support nodes and elements of set in create_bnf()
support nodes and elements of set in create_bnf()

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