only show popular tags when user doesn't set tags
now it can edit comment
it can change a book's booklist
ensure the time format of book_brief view
fix the bug that if a book is in many lists, the setting may be out of expectation
now it can set rating to a book
the rating in brief view also uses the star_black.png
now it can edit tags
hide the rating from others, display it as the hint while hovers on user's rating
fix a bug of unable to delete comment or tags
now random page redirect to the book's page; add guard for book_full to display comment or tags only when it's there;
now it will try fetch the book data from douban if it is not in local storage
fix the tostring method of fetchdataerror
when onebook page loads a book from douban, it will save it into local storage
now it can fetch all about a data, not just the shared info
now it can also parse and update the booklist info
it can confirm before user wants to remove a book from all lists
refactor the post handler for onebook page; add/change edit will turn a previously not-in-list book into done list
if remove from any list, the related tags, comment, rating will also be cleared
it can sync to douban (add or delete), edit will be ok in next commit