Cleanup bookstore demo
Cleanup bookstore demo

- Fix empty author label
- Move functions to the end
- Use appendTo consistently
- Minor renames

Change-Id: I30e58fffedb8ac3edde19ac05c2a3fa148ef801f

eclipsesource/tabris-js,mkostikov/tabris-js,eclipsesource/tabris-js,softnep0531/tabrisjs,moham3d/tabris-js,pimaxdev/tabris,pimaxdev/tabris,paulvi/tabris-js,softnep0531/tabrisjs,mkostikov/tabris-js,eclipsesource/tabris-js,moham3d/tabris-js