MatrixNormal density computation switched row and column covariance

There was a bug in density of MatrixNormal distribution. It showed only when number of rows was different from number of columns. For example:

                let m = [|[|1.0; 1.0|]|] |> DenseMatrix.ofColumnArrays
                let v = Double.DenseMatrix.CreateIdentity 2
                let k = Double.DenseMatrix.CreateIdentity 1
                let dist = MatrixNormal(m, v, k)
                let sample = dist.Sample()   // sampling from the distribution works
                dist.Density(sample)   // crashes

In the implementation, row covariance and column covariance matrices were switched.