Update to database-logs/move-rds-logs-to-s3/rds-logs-to-s3.py to acccount for log files larger than 1 MB

[dgrantX]

*Issue #70

*Description of changes: Added code to address issues found where RDS log file sizes are greater than 1 MB and audit requirements for archiving logs

• Handles RDS log files > 1 MB in size
• Handles Log file portions > 1 MB in size - by reducing NumberOfLines so db_log_file_portion < 1 MB
• Handles an edge case where logs get rotated as the log file is being downloaded
• Handles API throttling with geometric back off
• Creates an audit record of the program activity

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[mponizil]

This PR seems to fix the issue, though perhaps it hasn't been merged because there's kind of a lot going on. Can the maintainer comment about any next steps here? Even if this rendition isn't merged, it seems prudent that the script be updated with this recursion logic so that logs with long lines aren't mysteriously exported with missing data.