Stabilise MoveToWorld (#4004)

* Stabilise MoveToWorld

* Fix comments and deprecate ScheduleMoveToWorld

* Enhanced thread safety for m_WorldChangeInfo

* Return unique_ptr from cAtomicUniquePtr::exchange

* cWorld now calls entity cEntity::OnAddToWorld and cEntity::OnRemoveFromWorld.

Allows broadcasting entities added to the world from the world's tick thread.
This also factors out some common code from cEntity::DoMoveToWorld and cEntity::Initialize.

As a consequence, cEntity::Destroy(false) (i.e. Destroying the entity without broadcasting) is impossible.
This isn't used anywhere in Cuberite so it's now deprecated.

* Update entity position after removing it from the world.
Fixes broadcasts being sent to the wrong chunk.

* Fix style

* cEntity: Update LastSentPosition when sending spawn packet

* Add Wno-deprecated-declarations to the lua bindings

* Kill uses of ScheduleMoveToWorld

src/Mobs/Monster.cpp

@@ -132,12 +132,12 @@ cMonster::~cMonster()
 
 
 
-void cMonster::Destroy(bool a_ShouldBroadcast)
+void cMonster::OnRemoveFromWorld(cWorld & a_World)
 {
 	if (IsLeashed())
 	{
 		cEntity * LeashedTo = GetLeashedTo();
-		Unleash(false, a_ShouldBroadcast);
+		Unleash(false, true);
 
 		// Remove leash knot if there are no more mobs leashed to
 		if (!LeashedTo->HasAnyMobLeashed() && LeashedTo->IsLeashKnot())
@@ -146,7 +146,7 @@ void cMonster::Destroy(bool a_ShouldBroadcast)
 		}
 	}
 
-	super::Destroy(a_ShouldBroadcast);
+	super::OnRemoveFromWorld(a_World);
 }
 
 
@@ -282,7 +282,7 @@ void cMonster::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 		m_DestroyTimer += a_Dt;
 		if (m_DestroyTimer > std::chrono::seconds(1))
 		{
-			Destroy(true);
+			Destroy();
 		}
 		return;
 	}
@@ -590,6 +590,20 @@ bool cMonster::DoTakeDamage(TakeDamageInfo & a_TDI)
 
 
 
+void cMonster::DoMoveToWorld(const cEntity::sWorldChangeInfo & a_WorldChangeInfo)
+{
+	// Stop all mobs from targeting this entity
+	// Stop this entity from targeting other mobs
+	SetTarget(nullptr);
+	StopEveryoneFromTargetingMe();
+
+	super::DoMoveToWorld(a_WorldChangeInfo);
+}
+
+
+
+
+
 void cMonster::KilledBy(TakeDamageInfo & a_TDI)
 {
 	super::KilledBy(a_TDI);