Core/Spells: Fix spelleffect sanctuary

- No longer removes every attacker, but updates the visibility
  - Using that effect won't remove attackers that can still see through the stealth of the caster based on distance
- Ignores spells that were casted before or at the same time of that effect
- Trigger other needed spells when casting Shadowmeld

--HG--
branch : trunk

src/server/game/Entities/Unit/Unit.cpp

@@ -100,7 +100,7 @@ Unit::Unit(): WorldObject(),
 m_movedPlayer(NULL), IsAIEnabled(false), NeedChangeAI(false),
 m_ControlledByPlayer(false), i_AI(NULL), i_disabledAI(NULL), m_procDeep(0),
 m_removedAurasCount(0), i_motionMaster(this), m_ThreatManager(this), m_vehicle(NULL),
-m_vehicleKit(NULL), m_unitTypeMask(UNIT_MASK_NONE), m_HostileRefManager(this)
+m_vehicleKit(NULL), m_unitTypeMask(UNIT_MASK_NONE), m_HostileRefManager(this), m_lastSanctuaryTime(0)
 {
 #ifdef _MSC_VER
 #pragma warning(default:4355)

src/server/game/Entities/Unit/Unit.h

@@ -1774,6 +1774,7 @@ class Unit : public WorldObject
         void UpdateObjectVisibility(bool forced = true);
 
         SpellImmuneList m_spellImmune[MAX_SPELL_IMMUNITY];
+        uint32 m_lastSanctuaryTime;
 
         // Threat related methods
         bool CanHaveThreatList() const;