Better Book Shelfs

* lock states:
*   open (everyone can do anything)
*   closed (with key can open and edit/change state)
*   view (everyone can open, with key can edit and change state)
* copy book:
*   - when in view mode, copy books can be copied
*   - to create a copy book -> place book in shelf (written book name: 'nameOfBook<copy>'), set shelf to view mode.
*     then the book will be converted to a copy book.
*   - to remove copy function: rename book to 'nameOfBook<uncopy>' and set shelf mode to view
* fixed some bugs