message: Java: Updated release notes to include some recent contributions.
diff: # Release 1.4.0
  ## Major Features And Improvements
  +* Java:
  + * Generics (e.g., `Tensor<Integer>`) for improved type-safety (courtesy @andrewcmyers).
  + * Support for multi-dimensional string tensors.
  ## Bug Fixes and Other Changes
  * `tf.nn.rnn_cell.DropoutWrapper` is now more careful about dropping out LSTM
  