Fix waypoint insertion so it actually works

src/MissionManager/MissionController.cc

@@ -186,7 +186,7 @@ int MissionController::insertSimpleMissionItem(QGeoCoordinate coordinate, int i)
 
     _recalcAll();
 
-    return sequenceNumber;
+    return newItem->sequenceNumber();
 }
 
 int MissionController::insertComplexMissionItem(QGeoCoordinate coordinate, int i)
@@ -202,7 +202,7 @@ int MissionController::insertComplexMissionItem(QGeoCoordinate coordinate, int i
 
     _recalcAll();
 
-    return sequenceNumber;
+    return newItem->sequenceNumber();
 }
 
 void MissionController::removeMissionItem(int index)

src/MissionManager/SimpleMissionItem.cc

@@ -593,5 +593,10 @@ void SimpleMissionItem::setCoordinate(const QGeoCoordinate& coordinate)
 
 void SimpleMissionItem::setSequenceNumber(int sequenceNumber)
 {
-    _missionItem.setSequenceNumber(sequenceNumber);
+    if (_missionItem.sequenceNumber() != sequenceNumber) {
+        _missionItem.setSequenceNumber(sequenceNumber);
+        emit sequenceNumberChanged(sequenceNumber);
+        // This is too likely to ignore
+        emit abbreviationChanged();
+    }
 }