update Mapping.from_args() for no element groups
update Mapping.from_args() for no element groups

- update get_physical_qps(), get_mapping_data()

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