Add exception support in Boost initialisation only if needed
Add exception support in Boost initialisation only if needed

* Avoid extra loading overhead

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