update a comment for a method
add pattern in pwd field of signup page, let css verify it
use "range" input to set rating
the price could also be 0.0, such as 4521194
add more options to nav bar
add handlers for the newly added page
add method for refresh douban token when it expires; but it may not work? at least it could delete the token in datastore so user would be notified to grant again
add utf8 encoding for comment/tags while syncing a book
set limit of comment to be max: 350 characters
can choose to disconnect from douban now; auth douban in a new tab
format some coding style according to sublime's linter
remove imports in pages/__init__.py
remove extra imports in books/__init__.py
remove extra imports in utils/__init__.py
remove previous debugging tags
add paging to booklists; now only a fraction of books will be displayed