Class.DB.php: Database based on text CSV files

This class is capable of managing a database based on text files in the CSV format.

It runs integrated in PHP scripts and so it does not need a separate server.

It features file encryption and basic database management operations: find, replace and delete records.

It operates with numeric or associative field names.

It also also has a useful append mode for event logging.

File overwriting is interlocked with read to avoid losing updates written by other processes.