Jump obeys slow mid-air, wrecks continue inertially

the loop used to continue after unit died because it needed the fakeUnit (ie. the AA targetting feature); it could therefore theoretically be possible (near unit limit, or just super rarely) that some new unit who got the same unitID would continue on the dead jumper's track

now the conditional is split, and also uses ValidUnitID instead of GetUnitTeam to check for validity