Subtitle online search

Would be a useful feature to have an option to manually search for subtitles on various sites (ie under the Subtitles tab of a movie properties) similar to how Mediaplayer Classic HC can search for subs on popular sites like OpenSubtitles, podnapisim titlovi, subdb, ysubs ...etc

Thanks for the suggestion, we will consider adding this to a future version. Possibly something like https://github.com/Diaoul/subliminal might integrate well with Mezzmo since Mezzmo supports python.