Plumey fix and MM progress

Fix to the RealPlume MM config such that it properly NEEDS RealPlume, rather than being FOR RealPlume with NEEDS SmokeScreen. I've also removed reference to SmokeScreen as it's a depends from RealPlume anyway. Thanks @jsolson for the heads up.
There's also ongoing progress on the WIP Mission Module sections, although mostly just with the modelling, config still very lacking.