addurl behavior change: When downloading an url ending in .torrent,
it will download files from bittorrent, instead of the old behavior
of adding the torrent file to the repository.
Added Recommends on aria2 and bittornado | bittorrent.
This commit was sponsored by Asbjørn Sloth Tønnesen.
* New annex.hardlink setting. Closes: #758593
* init: Automatically detect when a repository was cloned with --shared,
and set annex.hardlink=true, as well as marking the repository as
untrusted.
Had to reorganize Logs.Trust a bit to avoid a cycle between it and
Annex.Init.
