swemc: Execute MySQL queries and output results in tables

This class can connect of a MySQL database, execute SQL query and output the query results in HTML tables.

It provides functions that can:

-Execute select, update, insert and delete SQL queries
-Output query results in HTML tables that can have their presentation customized with CSS.
-Output HTML tables also customizable with CSS with the results of queries that retrieve single database table records
-Retrieve specific query result values by column name or field number
-Retrieve a specific query result row by row number