Core/Spells: expand the single target aura system to support a specific amount of targets

* limit Living Bomb targets to three per caster

src/server/game/Spells/SpellInfo.cpp

@@ -1034,6 +1034,7 @@ SpellInfo::SpellInfo(SpellEntry const* spellEntry, SpellEffectEntry const** effe
     _auraState = AURA_STATE_NONE;
 
     _allowedMechanicMask = 0;
+    MaxAuraTargets = 0;
 }
 
 SpellInfo::~SpellInfo()