Imdbid from nfo and sync / sorting

Added to sort the most likely wanted subtitles on top even if moviehash search fails, added another condition to mark the subtitle as in sync.

Added support for fetching IMDB id from nfo.

Changed so that if a manual string is entered, that string is the only thing being searched for. Don't append the query string to the search if searching by moviehash or IMDB id succeeded, it returns to many unwanted results. Only use the query string in the search if moviehash and IMDB id search returns empty or if manual search or if it's a TV Show.
@fape did a nice PR https://github.com/xbmc/xbmc/pull/4458  where preferred language gets sent from xbmc. see here https://github.com/fape/service.subtitles.supersubtitles/commit/d64b3e13379cb754a6177b0b91665d08a8c40154