Torrents failing hash check should not re-download automatically

[skomorokh]

Wound up using a lot of bandwidth when a mountpoint didn't come online soon enough and all the torrents on that drive reset to 0%.

I can't think of any situation where I'd want to re-download something I was previously seeding without manual confirmation:

• if my storage is unavailable for some reason I want a chance to rectify

• if a file was corrupted by something the hash check gives me valuable info about my failing drive and I will totally not notice if it just silently re-fetches the missing chunks

• if I delete something I still had open in Deluge, well, I deleted it, I probably don't want it back

No idea about the architecture here but it would probably be as simple as a flag that gets set once a torrent begins seeding?

[Calum]

Duplicate of #1032