update FieldVariable.data_from_qp() for higher order approximations
update FieldVariable.data_from_qp() for higher order approximations

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