qtscript: Call the right event on transporter exit.

It used to be known as CALL_START_NEXT_LEVEL in wzscript,
but in fact this is the event of the transporter flying
far enough from the LZ to trigger the start
of the offworld mission.

It does not seem to cause ambiguity with the event
of the transporter actually crossing the map boundary
(eg., after landing on the away mission).

src/action.cpp

@@ -837,7 +837,7 @@ void actionUpdateDroid(DROID *psDroid)
 				{
 					//the script can call startMission for this callback for offworld missions
 					eventFireCallbackTrigger((TRIGGER_TYPE)CALL_START_NEXT_LEVEL);
-					triggerEvent(TRIGGER_START_LEVEL);
+					triggerEvent(TRIGGER_TRANSPORTER_EXIT, psDroid);
 				}
 			}
 		}

src/order.cpp

@@ -328,7 +328,7 @@ void orderUpdateDroid(DROID *psDroid)
 				{
 					// the script can call startMission for this callback for offworld missions
 					eventFireCallbackTrigger((TRIGGER_TYPE)CALL_START_NEXT_LEVEL);
-					triggerEvent(TRIGGER_START_LEVEL);
+					triggerEvent(TRIGGER_TRANSPORTER_EXIT, psDroid);
 				}
 			}
 		}
@@ -411,7 +411,7 @@ void orderUpdateDroid(DROID *psDroid)
 			{
 			    //the script can call startMission for this callback for offworld missions
 			    eventFireCallbackTrigger((TRIGGER_TYPE)CALL_START_NEXT_LEVEL);
-			    triggerEvent(TRIGGER_START_LEVEL);
+			    triggerEvent(TRIGGER_TRANSPORTER_EXIT, psDroid);
 
 				/* clear order */
 				psDroid->order = DroidOrder(DORDER_NONE);
@@ -1124,7 +1124,7 @@ void orderUpdateDroid(DROID *psDroid)
 				{
 					// the script can call startMission for this callback for offworld missions
 					eventFireCallbackTrigger((TRIGGER_TYPE)CALL_START_NEXT_LEVEL);
-					triggerEvent(TRIGGER_START_LEVEL);
+					triggerEvent(TRIGGER_TRANSPORTER_EXIT, psDroid);
 				}
 			}
 		}

src/transporter.cpp

@@ -1172,7 +1172,7 @@ bool updateTransporter(DROID *psTransporter)
 
 			//the script can call startMission for this callback for offworld missions
 			eventFireCallbackTrigger((TRIGGER_TYPE)CALL_START_NEXT_LEVEL);
-			triggerEvent(TRIGGER_START_LEVEL);
+			triggerEvent(TRIGGER_TRANSPORTER_EXIT, psTransporter);
 
 			// clear order
 			psTransporter->order = DroidOrder(DORDER_NONE);