Feature reuest for better filter model

[SNBogdanov]

Make more filters.
With current filter system there is no problem. It is not good for separating seeding and downloading torrents.
I.e.
Active. Seeding and downloading
Paused. Completed and not downloaded.
Downloading. Active and in Queue
Seeding. Active and in Queue.

It would be nice to have some kind of tree on top level filters.
Like Active includes Seeding and downloading. Expand tree and yuou have separate Active Seeding and Active Downloading.