Add Missile Boost and a few other missile tweaks

[RedDeadlyCreeper]

1 - Made ASMs use the new ATGM effect, particle effect is in ACF Main so add that, Merge pending 2 - Added Missile Boost, check the boost variable in BGMs to see variable format, only uses if defined 3 - Gravity Compensation tweak, makes slower missiles compensate more and faster not as much The above tweak leads to a straighter missile flight where they dip in the middle less.