Core/SmartAI: Various fixes and extensions for smart scripts:

Port From (https://github.com/TrinityCore/TrinityCore/commit/a32d5cfa1762ae1158ee2f40b4c9b36e5b41913a)

Source/Game/Entities/Creature/Creature.cs

@@ -1909,14 +1909,6 @@ namespace Game.Entities
             return searcher.GetTarget();
         }
 
-        public Player SelectNearestPlayer(float distance)
-        {
-            var checker = new NearestPlayerInObjectRangeCheck(this, distance);
-            var searcher = new PlayerLastSearcher(this, checker);
-            Cell.VisitAllObjects(this, searcher, distance);
-            return searcher.GetTarget();
-        }
-
         public void SendAIReaction(AiReaction reactionType)
         {
             AIReaction packet = new AIReaction();

Source/Game/Entities/GameObject/GameObject.cs

@@ -569,6 +569,11 @@ namespace Game.Entities
                                     SetLootState(LootState.JustDeactivated);
                                     return;
                                 }
+
+                                // Call AI Reset (required for example in SmartAI to clear one time events)
+                                if (GetAI() != null)
+                                    GetAI().Reset();
+
                                 // respawn timer
                                 uint poolid = GetSpawnId() != 0 ? Global.PoolMgr.IsPartOfAPool<GameObject>(GetSpawnId()) : 0;
                                 if (poolid != 0)
@@ -1305,7 +1310,7 @@ namespace Game.Entities
                 if (Global.ScriptMgr.OnGossipHello(playerUser, this))
                     return;
 
-                if (GetAI().GossipHello(playerUser, true))
+                if (GetAI().GossipHello(playerUser, false))
                     return;
             }
 

Source/Game/Entities/Object/WorldObject.cs

@@ -1544,6 +1544,14 @@ namespace Game.Entities
             return searcher.GetTarget();
         }
 
+        public Player SelectNearestPlayer(float distance)
+        {
+            var checker = new NearestPlayerInObjectRangeCheck(this, distance);
+            var searcher = new PlayerLastSearcher(this, checker);
+            Cell.VisitAllObjects(this, searcher, distance);
+            return searcher.GetTarget();
+        }
+
         public void GetGameObjectListWithEntryInGrid(List<GameObject> gameobjectList, uint entry = 0, float maxSearchRange = 250.0f)
         {
             var check = new AllGameObjectsWithEntryInRange(this, entry, maxSearchRange);

Source/Game/Entities/Unit/Unit.Combat.cs

@@ -3147,7 +3147,7 @@ namespace Game.Entities
             return true;
         }
 
-        bool IsValidAssistTarget(Unit target)
+        public bool IsValidAssistTarget(Unit target)
         {
             return _IsValidAssistTarget(target, null);
         }