discrepancy between root-sieved alpha and true alpha
Imported issue: Initially reported by Shi Bai in https://gforge.inria.fr/tracker/?group_id=2065&aid=21542
Paul suggested to looked at the discrepancy between root-sieved and true value. This also helps to understand the approximation quality of the ropt. In ropt_stage2.c, the root sieve scores are recorded in
Line 870 sievearray_t sa; where sa->array is an array of int16_t.