SmartMySQL: MySQL database access wrapper

This class implements a MySQL database access wrapper. It can:

- Establish connections to given MySQL database server host
- Execute SQL SELECT query to retrieve the value of a given table column with another column that has a given value
- Retrieve query results into an array
- Cache retrieved results for speed improvement
- Switch between fetch modes
- Generate insert and update type MySQL queries
- Escape string literal values
- Retrieve database access errors