Set flags of resumed/existing torrents

[l1meju1ce]

Allow users to set flags of resumed/existing torrents, such as no_verify_files, from an array in the config.toml.

[l1meju1ce]

And maybe only allow it to set flags of resumed/existing torrents that were finished/seeding before. Adding a default_dont_download flag to a torrent that's still downloading would be bad.