Improvements and fixes

• Updated subscriber threading model.
• Dynamic subtopic discovery.
• New CLI tools.
• Better logging.
• StreamKitHandler for logging standard library.

Minimum Viable Implementation

This release offers all principle features, behavior, and interfaces. It has been tested in Python 3.8 on Linux, macOS, and Windows 10 over SQLite3 and PostgreSQL 12. Still to come is code clean up, documentation, examples, recipes for log handling, and using TimescaleDB for automatic partitioning, compression, and data retention.