Minor DetailView changes

This PR has some minor improvements for DetailView (and a little cleanup):

- DetailView now shows a loading animation (like IGF) when the record is loaded (not when updating, only if isEmpty() returns true)
- fix for an NPE: if Add to list was pressed before the record was loaded the app crashed
- fix for manga ratings not saved
- fix Android Beam (NFC)
- little cleanup: 
  - search_item.xml: deleted because it's not used
  - card_detailview_synopsis.xml: the RelativeLayout around the TextView is not needed, so remove it