BlasPermutation.resize() does not work

[Breush]

See #90 for the clean-up discussion about permutations.

This code shows the problem:

#include <iostream>
#include <givaro/modular.h>
#include <linbox/matrix/dense-matrix.h>
#include <linbox/matrix/permutation-matrix.h>

int main(void) {
    using Field = Givaro::Modular<double>;
    using Matrix = LinBox::DenseMatrix<Field>;

    Field F(11);
    Matrix M(F, 2, 1);
    M.setEntry(0, 0, 0.0);
    M.setEntry(1, 0, 1.0);

#if 0
    LinBox::BlasPermutation<size_t> P(2);
    LinBox::BlasPermutation<size_t> Q(1);
#else
    LinBox::BlasPermutation<size_t> P;
    LinBox::BlasPermutation<size_t> Q;
    P.resize(2);
    Q.resize(1);
#endif

    LinBox::PLUQMatrix<Field>(M, P, Q);

    std::cout << P << std::endl;
    std::cout << Q << std::endl;
}

When the first (right) version is used:

[1,1](2)
[0](1)

When the second (failing) version is used:

[](2)
[](1)