"last activity" on stuck torrents is misleading

[kilobyte]

When you have a rare torrent, very often there's no seeder anymore, and everyone left has the same subset of data, Every once in a while, someone new joins, downloads what's available and becomes stuck with everyone else. But, uploading data to that new person counts as "activity", making this indicator useless.

Thus, what about:

• on incomplete torrents, only download should bump "activity"
• when seeding, uploading would count

That'd give a way to spot dead torrents, both those that are never going to complete, and those no one cares about anymore.

[lighterowl]

Sounds like very very much related to #951.