Cleaner integration of ply to the setup build.
Cleaner integration of ply to the setup build.

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