*   Adds a family= attribute in `tf.summary` ops to allow controlling the tab
    name used in Tensorboard for organizing summaries.
*   When GPU is configured, do not require --config=cuda, instead, automatically
    build for GPU if this is requested in the configure script.
*   Fix incorrect sampling of small probabilities in CPU/GPU multinomial.

#     nogcp:        Disable GCS support.
#     nohdfs:       Disable hadoop hdfs support.
#     nonccl:       Disable nccl support.
#
#
# Remote build execution options (only configured to work with TF team projects for now.)
#     rbe_base:  General RBE options shared by all flavors.
#     rbe_linux: General RBE options used on all linux builds.