* Added barcode scanner
* Fixed NPE if the device is offline
* Fixed missing whitespace in share_text string
* Changed about fragment appearance
* Fixed NPE when rotating device in BookDetail fragment by retaining it

* Fixed crash if a book has no author when adding a book
* Fixed crash in details view when book has no author
* Fixed crash on configuration change in details screen (caused by ActionProvider)
* Removed back button in details fragment