Enable book filters only for authenticated
Move book list to template and include it on home and book pages.

Book list is unordered list spanning 20 lines of code and the same
code is used in two places: home page where just a small sample of
books is displayed, and book list page where all books are displayed.
The code that can be reused is moved to a template and included where
needed.
Move status label to a template.

Status labels are rendered at two places in borrow request lists.
Move them to template to avoid code repetition.
Disable debugging in production.

Display user friendly messages to users in case of 404 or
500 errors.
Customize admin header - add link back to home page.