Fix Rothide Gnoll casting Curse of Thule

Fix Rothide Gnoll casting Curse of Thule on itself instead of casting it
on hostile target
Add AI scripts to Crypt Guard

AI scripts for Crypt Guard (adds to Anub'Rekan in Naxxramas) were
missing. Backported from WotLK branch.
Fix spell used by Naxxramas Acolyte

Naxxramas Acolyte was using a normal version of Arcane explosion instead
of the more powerful raid version it should use
Fix Plague Beast use of Mutated Spore

Plague Beast should cast Mutated Spore at spawn (it always have that
green aura) and not only when entering combat
Add AI script for Living Poison

Living Poison in Naxxramas now cast Explode when a player is in range (5
yards).
Add AI script for Toxic Tunnel

Toxic Tunnel casts channeled spell Toxic Gas in Naxxramas
Remove AI script for Velinde Shadowsong

Velinde Shadowsong is involved in 2 different quests scripts while ACID
handle one. These scripts were expanded and added to DB, thus ACID
script is removed.