The big NULL replacement party part 2.

This may take a bit. Trying to do this by operator/command.

src/LuaReference.cpp

@@ -112,7 +112,7 @@ int LuaReference::GetLuaType() const
 
 void LuaReference::Unregister()
 {
-	if( LUA == NULL || m_iReference == LUA_NOREF )
+	if( LUA == nullptr || m_iReference == LUA_NOREF )
 		return; // nothing to do
 
 	Lua *L = LUA->Get();