Fixes creatures aggro range, Wrong check on pathpoints, and a crash when there is no unitCaster.

Source/Game/Entities/Creature/Creature.cs

@@ -1786,10 +1786,10 @@ namespace Game.Entities
             float maxRadius = 45.0f * aggroRate;
             float minRadius = 5.0f * aggroRate;
 
-            uint expansionMaxLevel = Global.ObjectMgr.GetMaxLevelForExpansion((Expansion)GetCreatureTemplate().RequiredExpansion);
-            uint playerLevel = player.GetLevelForTarget(this);
-            uint creatureLevel = GetLevelForTarget(player);
-            uint levelDifference = creatureLevel - playerLevel;
+            int expansionMaxLevel = (int)Global.ObjectMgr.GetMaxLevelForExpansion((Expansion)GetCreatureTemplate().RequiredExpansion);
+            int playerLevel = (int)player.GetLevelForTarget(this);
+            int creatureLevel = (int)GetLevelForTarget(player);
+            int levelDifference = creatureLevel - playerLevel;
 
             // The aggro radius for creatures with equal level as the player is 20 yards.
             // The combatreach should not get taken into account for the distance so we drop it from the range (see Supremus as expample)

Source/Game/Movement/Generators/PathGenerator.cs

@@ -952,7 +952,7 @@ namespace Game.Movement
                 return;
 
             // check if we even need to do anything
-            if ((_pathPoints[0] - target).LengthSquared() >= distSq)
+            if ((_pathPoints[_pathPoints.Length - 1] - target).LengthSquared() >= distSq)
                 return;
 
             int i = _pathPoints.Length - 1;

Source/Game/Spells/Spell.cs

@@ -3372,7 +3372,7 @@ namespace Game.Spells
                 return;
 
             Unit unitCaster = m_caster.ToUnit();
-            if (unitCaster != null)
+            if (unitCaster == null)
                 return;
 
             // successful cast of the initial autorepeat spell is moved to idle state so that it is not deleted as long as autorepeat is active

Source/Scripts/Spells/Mage.cs

@@ -1018,7 +1018,7 @@ namespace Scripts.Spells.Mage
         }
     }
 
-    // 205021 - Ray of Frost
+    [Script] // 205021 - Ray of Frost
     class spell_mage_ray_of_frost : SpellScript
     {
         public override bool Validate(SpellInfo spellInfo)
@@ -1039,6 +1039,7 @@ namespace Scripts.Spells.Mage
         }
     }
 
+    [Script]
     class spell_mage_ray_of_frost_aura : AuraScript
     {
         public override bool Validate(SpellInfo spellInfo)