v1.18.0

• memory optimizations for large schemas (especially shareded schemas with lots of duplicates)
• add support for an http endpoint to support Prometheus metrics
• allow javascript filters to access the row query object
• javascript filters now run in the bootstrap process
• support for non-latin1 column names
• add --output_schema_id option
• better handling of packet-too-big errors from Kinesis
• add message.publish.age metric