Ability to Stop In-Progress HLS Transcodes

[oakesville]

This logic was rightly removed from Transcoder.java, so there should be a way to let users abort running HLS transcodes.

    if ("Transcoding".equals(liveStream.getMessage())) {
        if (liveStream.matchesItem(item)) {
            // stop and delete in-progress transcoding jobs for same file 
            try {
                //getDownloader(new URL(baseUrl + "/Content/StopLiveStream?Id=" + liveStream.getId())).retrieve();
                getServiceDownloader(new URL(baseUrl + "/Content/RemoveLiveStream?Id=" + liveStream.getId())).get();
            ...