The steady “drip-drip” of Prince-related material continues to be put out to his fans courtesy of his estate.  The latest arrival? rare and previously unseen music videos originally released between 1995-2010. Fans will start seeing videos appearing on YouTube today.  Videos for “Endorphinmachine,” “Dolphin,” and “Rock And Roll Is Alive! (And It Lives In Minneapolis)” are the first releases.  Fans can expect to see the videos in weekly batches.