Rework handling of Python comparison
Rework handling of Python comparison

In case of multiple comparisons, previous implementations evaluated all
arguments before doing the comparison. This is a bad behavior, as
evaluation of boolean expression are done lazily.

This improves the performance of the nqueens benchmarks a lot!

artas360/pythran,hainm/pythran,pombredanne/pythran,pbrunet/pythran,serge-sans-paille/pythran,pbrunet/pythran,hainm/pythran,pombredanne/pythran,serge-sans-paille/pythran,hainm/pythran,artas360/pythran,pbrunet/pythran,artas360/pythran,pombredanne/pythran