Parachute improvement

Start of the parachute improvement: https://github.com/KoffeinFlummi/AGM/issues/540
These is from an internal script I wrote a while back:
```
_refPoint1 = getPosASL (vehicle player);
_refPoint2 = +_refPoint1;
_refPoint2 set [2, (_refPoint1 select 2) - 1];
_intersects = lineIntersectsWith [_refPoint1, _refPoint2, (vehicle player), player];

if ((getPosATL (vehicle player) select 2) < 0.50 || (count _intersects) > 0) then ´
  // Land
}
```