MySQL class: MySQL wrapper with simultaneous query support

This class is a wrapper to access MySQL databases:

It supports:?

* Connecting to multiple servers at the same time
* Execute multiple SQL queries at the same time
* Retrieve unbuffered result sets with the possibility to a retrieval duration limit after which the connection thread is killed and the query is stopped
* Execute Insert, Update, Delete queries
* Retrieve the result set data as row array, row object, field, row associative array, etc.
* Execute raw queries