Implement MySqlConnection.ChangeDatabase

[rigofunc]

Currently, I user this package for test, I will dynamically change the database name, but I found the ChangeDatabase(string) method throw NotImplemtedException

public override void ChangeDatabase(string databaseName)
{
	throw new NotImplementedException();
}

[bgrainger]

This should be implemented by sending a COM_INIT_DB packet.

[bgrainger]

Implemented in 0.15.0.

[rigofunc]

so quickly, thanks! good job