Code cleanup in bookstore demo
Code cleanup in bookstore demo

- put layoutData in one line (remove clutter)
- refer widgets instead of their ids (this is supported now)
- omit rwt.widgets prefix (not required anymore)

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