Add "video/vnd.objectvideo" as supported MIME type.
Add support for pinning subscription to start.
Add support for MIME type "audio/x-mpeg"
Add support for yet another malformed podcast feed.

Thanks The Dan Patrick Show: Podcast
Generate unique file names for episodes so that we don't rely on unique file names from the stream.
Add possibility to delete all downloaded episodes in a subscription.
Add setting to control the threshold when an episode has been listened to.