Add auto link in case of existing URL in task.
Fix URL bug when the update process.
Fix URL bug when the moving status.
Add maxlength to text form.
Add left chars number for task form.
Improve display style of chars left length number.
Add moving between books by editing prefix.
Add TODO comment.
Improve effect of changing book name.
Add task number each books on top menu.
Add remove book feature (in progress)
Add remove book feature without display task counts each books on menu.
Edit text of remove book dialog.
Change delay time of moving task animation more short.
Remove no use valiable.
Refactoring task create logic without js.erb.
Refactoring move function about books from tasks_controller to books_controller.
Refactoring change books_controller methods to REST I/F.
Fixed #11
fixes #12