now the booklist can present a different brief view of books
add authors' intro when hover
add a OneBook page rendering a specific book; the title in booklists is a link to it
it can basically shows the prototype of rendering a specific book
add a cls method in BookRelated, it will collect all related info
now a book can show its shared info as it is in random page
also add gray background for tags in book_full
add the isbn validating method
exclude some SH___-___ isbns, they are old, but still there
show all related stuffs of a book