Core/Vehicles:

- Allow specifying of exit position for Unit::ExitVehicle
- On Vehicle::InstallAccessory, despawn any accessory in the current seat with the same entry with TEMPSUMMON_MANUAL_DESPAWN type
- Remove hacky TELEPORT_ACK packet on vehicle exit
- Remove some redundant packet send operations that were already handled elsewhere

src/server/game/Entities/Unit/Unit.cpp

@@ -16506,7 +16506,7 @@ void Unit::ChangeSeat(int8 seatId, bool next)
         ASSERT(false);
 }
 
-void Unit::ExitVehicle()
+void Unit::ExitVehicle(Position const* exitPosition)
 {
     if (!m_vehicle)
         return;
@@ -16525,23 +16525,26 @@ void Unit::ExitVehicle()
     if (!m_vehicle)
         return;
 
-    //sLog->outError("exit vehicle");
-
     m_vehicle->RemovePassenger(this);
 
     // This should be done before dismiss, because there may be some aura removal
     Vehicle *vehicle = m_vehicle;
     m_vehicle = NULL;
 
-    SetControlled(false, UNIT_STAT_ROOT);
+    SetControlled(false, UNIT_STAT_ROOT);       // SMSG_MOVE_FORCE_UNROOT
+
+    if (exitPosition)                           // Exit position specified 
+        Relocate(exitPosition);
+    else
+        Relocate(vehicle->GetBase());           // Relocate to vehicle base
 
     //Send leave vehicle, not correct
     if (GetTypeId() == TYPEID_PLAYER)
     {
         //this->ToPlayer()->SetClientControl(this, 1);
-        this->ToPlayer()->SendTeleportAckPacket();
         this->ToPlayer()->SetFallInformation(0, GetPositionZ());
     }
+
     WorldPacket data;
     BuildHeartBeatMsg(&data);
     SendMessageToSet(&data, false);