Core/Scripting: More fixes and updates for BRS Instance.

-trinityCore
Core: Fix non pch build
Core: Fix warnings
DB/Creature_template: A couple npc updates.
DB/Creature_text:
DB/Creature_text: And I forgot the text
Core/Scripting: Typo fix
Core/Scripting: Update npc_agnetta_tyrsdottar to use db gossip.