Config: Get config values from INI files XPath style

This class can be used to retrieve configuration values from INI files in XPath style.

It can open an INI format file given a path that includes the base name, section and setting that you want retrieve.

The class parses the file and returns the specified setting value.

The singleton pattern is used to keep a cache of previously parsed INI files in case multiple setting values need to be retrieved.

Example:
$conf = Config::singelton('myconf.ini');
$setting = $conf->getSetting('myconf/email/cc');