Sam MySQL Database Class: Wrap common MySQL database table SQL queries

This class wraps common MySQL database table SQL queries. It can:

- Perform SELECT queries and retrieve a single value, a single row into an array and all rows into a multidimensional array.
- Insert or update rows from a list of fields and values
- Delete table rows that satisfy a condition
- Count records in a given table
- Check if a table record exists with a given field value
- Perform a database search
- Return a certain number of rows of result from database, etc.