Change-Id: I0377e32aea55c3e85a40bc64eddf45c52846cac6
ORIGINAL_AUTHOR=Bartosz Przydatek <przydatek@google.com>

GitOrigin-RevId: c80cbaaf25e74ab8a7595e5192628d0f5d993a4c

- Directory structure follows TensorFlow.
- Rules for protobuf building are based on https://github.com/pubref/rules_protobuf, as I can't find anything simpler.
- Continuous integration with Kokoro (work in progress).

I also copied some existing Java/CC code from Bartosz and Daniel's experimental folders.

Change-Id: I7f993934d149c114320e3388fee84fbdafd7ba81