Scripts/Instance: The Vortex Pinnacle

More to come... Creature spawns and Grand Vizier Ertan for now.
- [ ] Slipstream
- [x] [**Grand Vizier Ertan**](http://www.wowhead.com/npc=43878)
 - [ ] Lurking Tempest
- [ ] [**Altairus**](http://www.wowhead.com/npc=43873)
- [ ] [**Asaad**](http://www.wowhead.com/npc=43875)

i will push another commit soon, this check will be removed. i guess pets aren't damaged since spell has SPELL_ATTR3_ONLY_TARGET_PLAYERS attribute