Changed ShoppingListDto, user is not @Parent now
add getByKeyString and getByKeyLong to AbstractFactoryPlus

getByKeyString - where string is a websafe string (key.getString())
getByKeyLong - for getting root objects with a long key
Refactor, user becomes parent of shoppinglist and methods expect keys

* ShoppongListManager : Instead of expecting long arguments, the methods
now expect keys
* ShoppingListService :
* /shoplist/all - list al shopping lists
* /shoplist/{id} - shows shopping list and its items, id is websafe
string key.