Pad fix

This set of commits stops the spawned craft from being forced to ground *through* the launchpad. Unfortunately, the spawned craft does not work yet as controls seem to be locked. Going to the space center and back to the craft allows some control, but the throttle gets stuck at about 10%. Still, no more explosions with an appropriate SpawnHeightOffset.

The code has been refactored a little and the spawned craft's flag is now set correctly.