Delicious Monster has been a well-known Mac developer for years, but has gone quiet in recent times as iOS apps have grabbed the lion’s share of attention. Now, the company is back with a new and improved version of its flagship app: Delicious Library 3 ($25). As always, it’s designed to help you inventory all the stuff in your life—books, DVDs, gadgets, and more. This newest edition adds social features, as well as a companion iOS…