Add deleteAndUpdateModel(entity)

OPEN - task 26: Add "Delete Item" functionalities
http://github.com/DevOpsDistilled/OpERP/issues/issue/26
@Inject ItemModel instead of ItemService and define deleteItem(item)

OPEN - task 26: Add "Delete Item" functionalities
http://github.com/DevOpsDistilled/OpERP/issues/issue/26
Add Test to test ItemController.deleteItem() (Also tests
EntityModel.deleteAndUpdateModel() )

OPEN - task 26: Add "Delete Item" functionalities
http://github.com/DevOpsDistilled/OpERP/issues/issue/26
Merge branch 'iss26-delete-item' into develop
Merge branch 'develop'