update Problem.get_evaluator(): allow a user evaluator Class specified in problem options
update Problem.get_evaluator(): allow a user evaluator Class specified in problem options

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