* @li If the value in the INI file is 'abc' and the default value an integer value, then validation
* fails and the method returns the default value;
* @li If the default value is a boolean value, then the method accepts '1', 'true', 'on' and 'yes' as valid values.
* @li If the value in the INI file is 'abc' and the default value an integer value, then validation
* fails and the method returns the default value;
* @li If the default value is a boolean value, then the method accepts '1', 'true', 'on' and 'yes' as valid values.