BigQuery

## wip.

### Docs: https://stephenplusplus.github.io/gcloud-node/#/docs/master/bigquery

Carrying on from #262. Just opening this so anyone interested can follow along.

These are still cases where they are using our API wrong. Those are the cases where we throw, so that they know with a serious warning, they need to try again with valid data. Their callback doesn't expect to handle errors with how they called our function, otherwise they would have called it properly the first time.