A fix-up release for 5.1.0.
- The bundled wallpaper is actually installed now.
- Spine folders open much faster.
- Face out the next unread book in a series, not just the first.
- A face-out reason ticked on its own now works; "Unread" alone never did.
- "Pages" in list rows is translatable, and so is the rest of the progress line (#418).
- The top panel's menu items say "top panel" rather than "book detail view".
- New installs open on Home / Recent / Series / Genres.
- Russian, and the shading and speed labels that shared one word across unrelated menus (#416, thanks @d1-m4ss).