*   Provided a new `experimental_skip_saver` argument which, if specified, will suppress the addition of `SavedModel`-native save and restore ops to the `SavedModel`, for cases where users already build custom save/restore ops and checkpoint formats for the model being saved, and the creation of the SavedModel-native save/restore ops simply cause longer model serialization times.

* Add ops to `tensorflow.raw_ops` that were missing.

* `tf.CheckpointOptions`

open the file at index `preferred_shard` in the list of matching files and try
to restore tensors from that file.  Only if some tensors or tensor slices are
not found in that first file, then the Op opens all the files. Setting
`preferred_shard` to match the value passed as the `shard` input
of a matching `Save` Op may speed up Restore.  This attribute only affects