Deleting entries and navigating by author in Site Updates

Yes, yes! You can delete entries now! Seemed like an important feature so I took care of it (don't worry, there's a confirmation screen so you won't accidentally delete your entry). There are still a lot of other things you can't delete yet, but I'll do that at some point soon.

Also, I added an extra navigation tab. You can now easily navigate through the current author's entries as well as the current book and your bookmarks. In fact, I'm going to write a Tips and Tricks entry to explain a bit better in case people haven't figured out the navigation tabs yet.