This will be implemented in the child class depending on config file type.
A system configuration file in the form of an INI file. These are in the standard NAME=VALUE format, within sections. In this class we ignore the [sections], and just read in all of the NAME=VALUE pairs, stashing them into the 'settings' class var as an array.
Constructor Open the given file for input.
The inputfile class manages files for input. It opens, reads and closes files in input-only mode.