Deletes a specific item selected by specifying its type and
        handle.
      deleteItem( type, handle, onSuccess, onFailure )
    
This method does not return anything.
          | Name | Description | Type | Use | 
          | type | Denotes the type of data to be deleted. | string | required | 
          | handle | Denotes the handle of data to be deleted. | string | required | 
          | onSuccess | A callback function, called after the data item is successfully deleted. | function | required | 
          | onFailure | A callback function, called when the operation fails. Returns an error code, as
            defined in the Constants table in the Client Store article. | function | required |