[TW231] - Core/Scripts: Reapply Elder Nadox's update

Should spawn only one guardian, was previously reverted due to merge conflicts
[TW232] - Core/Scripts: Ensure the Ancient Wolf casts its periodic trigger for the quest A Spirit Guide
[TW232] - Core/Scripts: Clean up remaining Flash Freezes after Hodir's done, fixes combat bug
[TW233] - Core/Scripts: Make use of a very old MaNGOS hack to implement Hodir's hard mode achievement

...please help me figure why the criteria doesn't trigger properly so we can clean this up.
[TW234] - Core/Scripts: Implement achievement Cheese the Freeze
[TW235] - Core/Scripts: Implements achievement I Have the Coolest Friends
[TW236] - Core/Scripts: Make Zombiefest! credit count instance wide (seeing wowhead comments it should be that way)
[TW237] - Core/Scripts: Implement Staying Buffed All Winter and Getting Cold In Here
[TW238] - Core/Scripts: Fixes Hadronox ignoring attackers while moving up the tunnel, he'll stop ascending when entering combat