Invisible/Hide mechanics when cast on

Updated mechanics to be consistent with live regarding how invisible breaks when the client is the target of a spell.
Invisible will drop whenever a client is hit with a detrimental spell, regardless of if resisted, if it does damage or AOE.
Hide skill now also follows the same rules as above.
Implemented support for Rogue AA - Nerves of Steel which gives a chance for hide NOT to break
when client is hit with an AOE spell.

zone/common.h

@@ -471,6 +471,7 @@ struct StatBonuses {
 	uint16  ReduceFallDamage;					// reduce fall damage by percent
 	int32	ReduceTradeskillFail[HIGHEST_SKILL+1]; // Reduces chance for trade skills to fail by percent.
 	uint8	TradeSkillMastery;					// Allow number of tradeskills to exceed 200 skill.
+	int16	NoBreakAESneak;						// Percent value
 };
 
 typedef struct