regular op now handles batches as well. All `batch_*` Python interfaces were
    removed.
*   `tf.all_variables`, `tf.VARIABLES` and `tf.initialize_all_variables` renamed
    to `tf.global_variables`, `tf.GLOBAL_VARIABLES` and
    `tf.global_variables_initializer` respectively.
*   `tf.zeros_initializer()` and `tf.ones_initializer()` now return a callable