[F] 2.44f: Filter result wrong after new sort

[Florian]

@Oblio

Almost. With new unofficial 2.44f the selection state is not preserved when sorting on column with filter active.

Confirmed, will fix that.

@gvm

In addition, selection state isn't preserved correctly when the filter is changed and the newly-selected set of files overlaps with the previously-selected set.

I currently see no way of preserving the selection state in such cases.