N1QL now returns status code 200 on error.

Performing a N1QL query on Watson builds will return status code 200 when errors occur. The specific example I have encountered is that doing a `CREATE PRIMARY INDEX` query will return an error if the index already exists, but the status code is 200. Note that this will break compatibility between older SDK clients and newer server versions, as it was previously assumed that N1QL would indicate an error when an error occurred.