Core/Misc: fix interaction of spells like Shadowmeld with Threat reducing effects

- SPELL_AURA_MOD_TOTAL_THREAT should be temporary and not added/subtracted from total, only computed
- Cleanup of reference related code
- Kill getLast() and reverse iterator obsevers, LinkedList iterator can't be used as a standard reverse_iterator (ie with operator++). They weren't used anyways

(cherry picked from commit 3b6fd226bedb689847dadaeeba36a588ee9bc928)

# Conflicts:
#	src/server/game/Combat/ThreatManager.cpp
#	src/server/game/Loot/LootMgr.h

1 files changed, 4 insertions, 4 deletions

diff --git a/src/server/game/Combat/HostileRefManager.cpp b/src/server/game/Combat/HostileRefManager.cpp
index 2c977f61941..e6153f0acff 100644
--- a/src/server/game/Combat/HostileRefManager.cpp
+++ b/src/server/game/Combat/HostileRefManager.cpp
@@ -28,8 +28,8 @@ HostileRefManager::~HostileRefManager()
 }
 
 //=================================================
-// send threat to all my hateres for the victim
-// The victim is hated than by them as well
+// send threat to all my haters for the victim
+// The victim is then hated by them as well
 // use for buffs and healing threat functionality
 
 void HostileRefManager::threatAssist(Unit* victim, float baseThreat, SpellInfo const* threatSpell)
@@ -37,9 +37,10 @@ void HostileRefManager::threatAssist(Unit* victim, float baseThreat, SpellInfo c
     if (getSize() == 0)
         return;
 
-    HostileReference* ref = getFirst();
     float threat = ThreatCalcHelper::calcThreat(victim, iOwner, baseThreat, (threatSpell ? threatSpell->GetSchoolMask() : SPELL_SCHOOL_MASK_NORMAL), threatSpell);
     threat /= getSize();
+
+    HostileReference* ref = getFirst();
     while (ref)
     {
         if (ThreatCalcHelper::isValidProcess(victim, ref->GetSource()->GetOwner(), threatSpell))
@@ -54,7 +55,6 @@ void HostileRefManager::threatAssist(Unit* victim, float baseThreat, SpellInfo c
 void HostileRefManager::addTempThreat(float threat, bool apply)
 {
     HostileReference* ref = getFirst();
-
     while (ref)
     {
         if (apply)