Eigen: viennalcl::copy GPUVector from EigenMatrix( Dynamic, Dynamic )

[chkone]

Hello,

I propose this fix to support Eigen Matrix with dynamic column to with an assert.

`template<typename NumericT, unsigned int AlignmentV>
void copy( vector<NumericT, AlignmentV> const & gpu_vec,
Eigen::Matrix<NumericT, Eigen::Dynamic, Eigen::Dynamic> & eigen_mat)
{
assert( eigen_mat.cols() == 1 && "copy vector to matrix not a single column: not compatible" );
viennacl::fast_copy( gpu_vec.begin(), gpu_vec.end(), &( eigen_mat[ 0 ] ) );
}

template<typename NumericT, unsigned int AlignmentV, int EigenMapTypeV, typename EigenStrideT>
void copy( vector<NumericT, AlignmentV> const & gpu_vec,
Eigen::Map<Eigen::Matrix<NumericT, Eigen::Dynamic, Eigen::Dynamic>, EigenMapTypeV, EigenStrideT> & eigen_mat )
{
assert( eigen_mat.cols() == 1 && "copy matrix (not a single column) to vector: not compatible" );
viennacl::fast_copy( gpu_vec.begin(), gpu_vec.end(), &( eigen_mat[ 0 ] ) );
}`

And for symmetry:
`template<typename NumericT, unsigned int AlignmentV>
void copy( vector<NumericT, AlignmentV> const & gpu_vec,
Eigen::Matrix<NumericT, Eigen::Dynamic, Eigen::Dynamic> & eigen_mat)
{
assert( eigen_mat.cols() == 1 && "Dimensions not compatible" );
viennacl::fast_copy( gpu_vec.begin(), gpu_vec.end(), &( eigen_mat( 0, 0 ) ) );
}

template<typename NumericT, unsigned int AlignmentV, int EigenMapTypeV, typename EigenStrideT>
void copy( vector<NumericT, AlignmentV> const & gpu_vec,
Eigen::Map<Eigen::Matrix<NumericT, Eigen::Dynamic, Eigen::Dynamic>, EigenMapTypeV, EigenStrideT> & eigen_mat )
{
assert( eigen_mat.cols() == 1 && "Dimensions not compatible" );
viennacl::fast_copy( gpu_vec.begin(), gpu_vec.end(), &( eigen_mat( 0, 0 ) ) );
}`

Cheers this is the version I use locally