Core/Players: Don't set instanceId to 0 when player is on transport during loading, there CAN be transports inside instances

Core/Scripts: Added waypoint id to OnRelocate transport hook
Core/Scripts: Make use of ZoneScript::GetGameObjectEntry at gameobject creation (makes it possible to override gameobject entries in instances)
Core/Transports: Call InstanceScript::EventInform for transport events
Core/Transports: Use guid from db for transports, not just its entry - adds partial support for instancing them (still cannot use transports table for it, but can spawn manually now)
Scripts/Icecrown Citadel: Fixed crash in Deathbringer Saurfang when event is started by more than one person (can't do this anymore)

Closes isssue #3749.

--HG--
branch : trunk

sql/base/world_database.sql

@@ -26721,11 +26721,13 @@ DROP TABLE IF EXISTS `transports`;
 /*!40101 SET @saved_cs_client     = @@character_set_client */;
 /*!40101 SET character_set_client = utf8 */;
 CREATE TABLE `transports` (
+  `guid` int(10) unsigned NOT NULL AUTO_INCREMENT,
   `entry` mediumint(8) unsigned NOT NULL DEFAULT '0',
   `name` text,
   `period` mediumint(8) unsigned NOT NULL DEFAULT '0',
   `ScriptName` char(64) NOT NULL DEFAULT '',
-  PRIMARY KEY (`entry`)
+  PRIMARY KEY (`guid`),
+  UNIQUE INDEX `idx_entry` (`entry`)
 ) ENGINE=MyISAM DEFAULT CHARSET=utf8 ROW_FORMAT=FIXED COMMENT='Transports';
 /*!40101 SET character_set_client = @saved_cs_client */;