Now torrents are downloaded with vfs.libtorrent[1].
Some parts of the code were removed as they will probably be useless
in the future. For instance, the service is disabled (temporarily?)
because the download in background/foreground is now managed by
vfs.libtorrent.
Use the Read() API of vfs.libtorrent to retrieve the path where the
torrent was downloaded.
Also:
* Display a warning if there are more than 1 file in the torrent
because the add-on will play only the first file
* Remove the "start downloading" notification since an equivalent
message is now displayed by vfs.libtorrent
[1]:https://framagit.org/thombet/vfs.libtorrent
* Convert settings.xml to the new format supported in Kodi 19
* Create help strings to guide the users
Note: the translation of the new help strings in German is missing.
While adding the German translation some encodings errors occurred due
to non-ASCII characters. Only these errors were fixed because a full
analysis of the strings will be performed when implementing support for
python3.