Well the validation errors that `node-restify-validation` currently outputs follow an odd syntax; for example:

```
{
    "error": "invalid_request",
    "scope": "params",
    "validation": {
        "_user": {
            "code": "MISSING",
            "field": "_user",
            "message": "Field is required"
        }
    }
}
```

It's perfectly adequate for now, but I think they could be simplified and made more consistent with the error format we're using for non-validation errors.