clean up script/eval_tl_forms.py, update for current sympy
clean up script/eval_tl_forms.py, update for current sympy

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