PET BATTLE XP CHANGED

Fired when a battle pet gains experience during a pet battle.
 PET_BATTLE_XP_CHANGED: owner, petIndex, xpChange
==Payload==
:;owner: - team to which the pet belongs, 1 for the player's team, 2 for the opponent.
:;petIndex: - pet index within the team.
:;xpChange: - amount of XP gained.
==Details==
* The PetJournal and PetBattles APIs still return the old level/experience information for the pet when this event fires.
==Patch changes==