mysql_driver: MySQL access wrapper to simplify common queries

This class is a MySQL database access wrapper that can be used to simplify the execution of common types of SQL queries and database access tasks. It can:

- Establish connections to a MySQL database server
- Setup transactions
- Executing SQL queries checking first if the database connection is still valid
- Retrieve query results into arrays
- Check, list, lock, retrieve descriptions and fields, and create tables
- Import and export the contents of one or more tables to CSV files]
- Insert, update, select and delete rows of tables from lists of parameters