TODO:
    * should show "Lost" books

    * add in Witcher books
        The Last Wish
        Sword of Destiny
        Blood of Elves
        Time of Contempt
        Baptism of Fire
        The Tower of the Swallow
        The Lady of the Lake
        Season of Storms (optional; explained below)

    * book.parent is an array, not a dict - should change it over

    * search, probably all books.html, don't deal with sub books and/or series ordering.  Probably should at least do subs ordering (so the code I wrote for author/<id>/books) and use that for search for example
        - test with search for 'dune'

    * search on more than title, e.g. author, series, etc.

    * if we add a new parent book with sub-books into a series, with parent * book as 'null' sub_book_num, all the sub_books should be added somehow into series - but cant input numbering on parent book, so
        - don't allow adding parent, use a pop-up saying, add the first-child, and then auto-number from there

    * consider removing all direct sqls and using ORM properly:
        - grep 'with db.engine' *.py