Scripts/Icecrown Citadel: Fixed Muradin/Saurfang attacking each other during Gunship Battle

Closes #11786
Core/SAI: Implement two new event types that are triggered when a certain creature/gameobject entry or guid gets within a given distance of the source.
Core/SAI: Only allow SMART_EVENT_TARGET_BUFFED to be used from creature sources.
Core/SAI: Allow only creature sources to use the event types SMART_EVENT_DISTANCE_CREATURE and SMART_EVENT_DISTANCE_GAMEOBJECT for now.
Quest: The Power of the Elements

Remove hack SAI, use aura script
Fix non-pch build and remove blank line
Quest: Direhorn Raiders

Remove duplicate kill credit