NoGaOS Cloud provider 15.

- `nogaos-cloud-15.jar`: the server, for Lambda and for `java -jar` on any machine.
- `nogaos-cloud-15-userpool.yaml`, `nogaos-cloud-15-data.yaml`, `nogaos-cloud-15.yaml`: the CloudFormation templates that run it on AWS, launched in that order.
- `protocol.md`: the protocol it speaks.

Setup: see `cloud/README.md` in the NoGaOS repository.
