Updated n_is_prime_pocklington so that it is compatible with C90
Updated n_is_prime_pocklington so that it is compatible with C90

wbhart/flint2,jpflori/flint2,dsroche/flint2,jpflori/flint2,fredrik-johansson/flint2,dsroche/flint2,dsroche/flint2,wbhart/flint2,dsroche/flint2,wbhart/flint2,jpflori/flint2,jpflori/flint2,fredrik-johansson/flint2,fredrik-johansson/flint2