Scripts/Icecrown Citadel: Add script for Deathbringer Saurfang (only missing alliance outro due to need of spawning and moving a transport)

Scripts/Icecrown Citadel: Corrected Lord Marrowgar, should no longer target tanks with Bone Spike Graveyard, his Coldflame should now spread properly
Core/Scripts: Moved Lady Deathwhisper Mana Barrier handler to scripts
Core/Scripts: Allow AuraScript to prevent default effects by effect index
Core/Scripts: Added Is25ManRaid() method to ScriptedAI, obviously used to check if raid is 25man
Core/Achievements: Pass m_caster to UpdateAchievementCriteria for ACHIEVEMENT_CRITERIA_TYPE_BE_SPELL_TARGET

--HG--
branch : trunk

src/server/game/Spells/Auras/SpellAuraEffects.cpp

@@ -2268,14 +2268,6 @@ void AuraEffect::TriggerSpell(Unit * target, Unit * caster) const
                     case 39857: triggerSpellId = 39856; break;
                     // Personalized Weather
                     case 46736: triggerSpellId = 46737; break;
-                    // Mana Barrier - Lady Deathwhisper
-                    case 70842:
-                    {
-                        int32 missingHealth = caster->GetMaxHealth() - caster->GetHealth();
-                        caster->ModifyHealth(missingHealth);
-                        caster->ModifyPower(POWER_MANA, -missingHealth);
-                        return;
-                    }
                 }
                 break;
             }