#238: Respect context path in client's url option.
#240: Add helpers to let users choose how to deserialize dateTime:RFC3339 query response data type.
#248: Change default InfluxDB URL to http://localhost:8086 .
#250: Simplify precision for WriteApi retrieval.
#253: Allow to simply receive the whole query response as a string.
#257: Regenerate APIs from swagger.

#258: Convert FluxTableColumn and FluxTableMetaData to interface. This change is unlikely to cause any harm, since the clients are expected to use only FluxTableColumn/FluxTableMetaData fields or methods that didn't change. See #258 for details and backward compatibility notes.

#237: Fixed line splitter of query results that might have produced wrong results for query responses with quoted data.
#242: Repair escaping of backslash in line protocol string field.
#246: Throw error on attempt to write points using a closed WriteApi instance.
#252: Repair nesting of flux expressions.
#259: Finish query when cancelled by the user.