Partial Archiving

[lenntt]

It would be great if plaintasks would really had a notion of 'subtasks' (instead of making them collapsible/expandable). There are already a few issues for things relating to that and because I expect this to be rather hard to implement, I've decided to file an issue for a probably easier thing to most, for it is the thing thats bothering the most:

I would like to archive all done issues, except for the ones that are subtasks of which the parent isn't done yet.