gsg: update Field.setup_extra_data()
gsg: update Field.setup_extra_data()

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