Settings update - RA2 MIX loading

- Added an argument "-MODNAME=XXX" that makes the editor load the
specified mod's config file (its ID like RA2 placed at XXX)
- Added an option to enable obsolete/disabled settings in the editor
(such as IonImmune for TeamTypes and PercentBuilt for Houses)
- Added in the 'correct' loading order of MIX files of Red Alert 2
(hence the quotation marks, it's from IDA and unconfirmed)