## Three bugfixes for missing_DiffuseKalmanSmootherH1_Z.m that led to wrong results

- In case of missing observations ('if isempty(di)'),
`a(:,t)`

was not propagated forward to update`a(:,t+1)`

- In the rank-deficient
`Finf`

case,`Kstar`

was defined as`T^(-1)*K^{(0)}`

, while in the full rank it was defined as`Kstar=K^(0)`

This leads to wrong results when switches between the two clauses occurr. Moreover, the later backwards pass relied on`Kstar=K^(0)`

, leading to wrong results when the rank-deficient`Finf`

case was triggered earlier. - In the rank-deficient
`Finf`

case, the backward pass did not use the proper formulas, but rather the ones for the non-singular case

The implementation now consistently follows the one in `kalman_filter_d.m`