Update SABnzbd to 7.20

- Updates SABnzbd to 7.20, ref #1376
- Convert pybundle to wheel, hopefully #1379 would be solved with that. See below
- Fix port to 8080 for new installs, ref #1351

@Diaoul, not sure if you'd want to replace the .cgi with the more conventional config for the shortcut, but that's easy enough to do.