Revert "Revert "newer standards prefer nullptr over NULL - this is most of them but there are others too""

This reverts commit 8e2160f33e.

engine/shared/library/sharedMessageDispatch/src/shared/Emitter.cpp

@@ -31,7 +31,7 @@ struct Emitter::ReceiverList
 Emitter::Emitter() :
 receiverList(new ReceiverList)
 {
-	assert (receiverList != NULL);
+	assert (receiverList != nullptr);
 }
 
 //---------------------------------------------------------------------

engine/shared/library/sharedMessageDispatch/src/shared/Receiver.cpp

@@ -33,7 +33,7 @@ Receiver::Receiver() :
 emitterTargets(new EmitterTargets),
 hasTargets(false)
 {
-	assert(emitterTargets != NULL);
+	assert(emitterTargets != nullptr);
 }
 
 //---------------------------------------------------------------------