Kafkacrypto

This version fixes a bug in the new flush implementation in confluent_kafka_wrapper that was necessary to work around an issue in librdkafka. Unfortunately, the original implementation did not respect being multi-threaded safe, and would thus encounter scenarios where flush would never return. Fix that by properly checking the number of messages remaining to be produced, in addition to tracking the number of messages produced within each thread calling poll. Also adds a timeout to all flush calls to reduce the impact of any such related bugs.

This version adds compatibility for Python 3.10, and adds a work-around for a nasty bug in librdkafka 1.8.0 (persists up to at least 1.8.2) that caused an inability to send subscribe messages and (eventually) resulted in memory corruption and a crash of the management thread.

This version adds logging rate limiting for certain messages that can occur at high frequency, and also improves readability of chain information on errors.

This release includes two changes:
1. adding compatibility with msgpack 1.0.0, principally the storing of bytes[] as bin8/16/32 instead of str.
2. fix regex constraint comparisons to allow the special case of a "match everything" regex in choices.

This release includes a number of important bugfixes, including:
1. adding compatibility with msgpack 1.0.0.
2. as part of 1, added appropriate str/bin support in a backwards-compatible fashion that will, once all systems are running 0.9.9.6 or later, enable switching off of the compatibility components with full msgpack 1 support.
3. ensure appropriate logging levels are always set.
4. fix regex constraint comparisons to allow the special case of a "match everything" regex.