Ensure craft vessel has a valid orbit

This is in the build cost calculation only, but does take care of the
vessel being ripped out from underneath EL while calculating the cost
due to ObT being nan. It looks like this is the same cause for the
breakdown when actually building a survey stake, but that might be a
little trickier to sort out.

Source/BuildControl.cs

@@ -1158,6 +1158,10 @@ public CostReport getBuildCost (ConfigNode craft, string craftText = null)
 				lockedParts = true;
 			}
 			GameObject ro = ship.parts[0].localRoot.gameObject;
+			var od = ro.GetComponent<OrbitDriver> () ?? ro.AddComponent<OrbitDriver> ();
+			od.orbit = new Orbit(builder.vessel.orbit);
+
+			EL_Utils.dumpxform (ro.transform, true);
 			Vessel craftVessel = ro.AddComponent<Vessel>();
 			craftVessel.vesselName = "EL craftVessel - " + craft.GetValue ("ship");
 			craftVessel.Initialize (true);