change argument names in EStokesTerm.get_function() according to other terms
change argument names in EStokesTerm.get_function() according to other terms

vlukes/sfepy,sfepy/sfepy,vlukes/sfepy,BubuLK/sfepy,BubuLK/sfepy,vlukes/sfepy,sfepy/sfepy,rc/sfepy,sfepy/sfepy,rc/sfepy,BubuLK/sfepy,rc/sfepy