[Core/Threat] SpellThreat-Calculation revamped

short:
  - Threat is now distributed blizzlike (almost)

long:
  - Percent- and AP-Modifieres got add
  - Threat is now propperly distributed through multiple enemies
  - Most spells will cause initial threat in an amount equal to their SpellLevel
  - Energize-Effects will now be treated like healing (threat-wise)
  - Tanks got their missing +43% passive threat tacked on
  - Paladins are still missing 'Salvation' and will not only cause half threat with healing (essentially 25% of the amount healed)

src/server/game/Combat/HostileRefManager.cpp

@@ -40,10 +40,9 @@ void HostileRefManager::threatAssist(Unit* victim, float baseThreat, SpellInfo c
     threat /= getSize();
     while (ref)
     {
-        if (victim == getOwner())
-            ref->addThreat(threat);          // It is faster to modify the threat durectly if possible
-        else
-            ref->getSource()->addThreat(victim, threat);
+        if (ThreatCalcHelper::isValidProcess(victim, ref->getSource()->getOwner(), threatSpell))
+            ref->getSource()->doAddThreat(victim, threat);
+
         ref = ref->next();
     }
 }

src/server/game/Combat/ThreatManager.cpp

@@ -36,8 +36,14 @@ float ThreatCalcHelper::calcThreat(Unit* hatedUnit, Unit* /*hatingUnit*/, float
 {
     if (threatSpell)
     {
-        if (threatSpell->AttributesEx & SPELL_ATTR1_NO_THREAT)
-            return 0.0f;
+        if (SpellThreatEntry const*  threatEntry = sSpellMgr->GetSpellThreatEntry(threatSpell->Id))
+            if (threatEntry->pctMod != 1.0f)
+                threat *= threatEntry->pctMod;
+
+        // Energize is not affected by Mods
+        for (uint8 i = 0; i < MAX_SPELL_EFFECTS; i++)
+            if (threatSpell->Effects[i].Effect == SPELL_EFFECT_ENERGIZE || threatSpell->Effects[i].ApplyAuraName == SPELL_AURA_PERIODIC_ENERGIZE)
+                return threat;
 
         if (Player* modOwner = hatedUnit->GetSpellModOwner())
             modOwner->ApplySpellMod(threatSpell->Id, SPELLMOD_THREAT, threat);
@@ -46,7 +52,7 @@ float ThreatCalcHelper::calcThreat(Unit* hatedUnit, Unit* /*hatingUnit*/, float
     return hatedUnit->ApplyTotalThreatModifier(threat, schoolMask);
 }
 
-bool ThreatCalcHelper::isValidProcess(Unit* hatedUnit, Unit* hatingUnit, SpellInfo const* /*threatSpell*/)
+bool ThreatCalcHelper::isValidProcess(Unit* hatedUnit, Unit* hatingUnit, SpellInfo const* threatSpell)
 {
     //function deals with adding threat and adding players and pets into ThreatList
     //mobs, NPCs, guards have ThreatList and HateOfflineList
@@ -68,6 +74,10 @@ bool ThreatCalcHelper::isValidProcess(Unit* hatedUnit, Unit* hatingUnit, SpellIn
     if (!hatedUnit->isAlive() || !hatingUnit->isAlive())
         return false;
 
+    // spell not causing threat
+    if (threatSpell && threatSpell->AttributesEx & SPELL_ATTR1_NO_THREAT)
+        return false;
+
     ASSERT(hatingUnit->GetTypeId() == TYPEID_UNIT);
 
     return true;