Properly set labels to new torrents in uTorrent

Labels were not always set to new torrents in utorrent (i.e. for torrents from PublicHD). The problem was that sickbeard was unable to locate the correct torrent to set the label to.

*Cleaned up uTorrent API implementation based on flex1986 code
*Fixed cases were uTorrent label were not set

Also included the fix for the missing provider cookie from the previous pull request.