clean up sfepy/discrete/conditions.py
clean up sfepy/discrete/conditions.py

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