Uses List<string> instead of ArrayLists

Fixed the load typo to Load

Changed the set function to have the subSection first. It's much more intuitive and looks more organized when setting multiple variables. It was visually awkward to separate the key from the value.
Ex. 
        parser.Set("graphics", "resolution", "1920x1080");
        parser.Set("graphics", "antiAlias", "8", "Can only be: 0, 1, 2, 4, 8");
        parser.Set("audio", "mode",  "sterio");
        parser.Set("audio", "masterLevel",  "100", "Can only be 0 - 100");
        parser.Set("audio", "musicLevel",  "75");

Removed the ToString() calls.

Added using to the Save function to keep it consistent with the Load function.

Removed Close() from the Save and Load function, because using closes automatically.