Remove global "cleanup settings".

All of those are now subscriptions specific.
Implement "Mark all listened".
Fix "NewEpisodeVisibility" property changed.
Don't fail the whole podcast if the <link> property is empty.,

If <link> is empty, then the title is used as the link - just to identify podcasts when looking for duplicates.
Fix binding of podcast subscriptions to the "PodcastSubscriptions" property.
Fix subscriptions setting's text.
Again some DB issues.
Force redraw of subscriptions model when returning to main view.

Maybe not the cleanest solution, but feels right at this moment.
Update the PrimaryTile with the podcast info that's being played.