barcode callback
barcode and addbook callback
better addBook()    |   bookListView
Merge pull request #35 from phil5/master

'barcode' and 'addbook' to 'bookview'
Merge pull request #36 from Nihiue/master

better addBook()    |   bookListView
new BookListView
Merge pull request #37 from Nihiue/master

new BookListView
fix a bug when no people found
finish yoo