rest of virtuals removed

virtuals removed and replaced with override where necessary on the rest of the code base, clang-tidy to the rescue.

Engine/source/platform/async/asyncBufferedStream.h

@@ -151,7 +151,7 @@ class AsyncBufferedInputStream : public IInputStreamFilter< T, Stream >,
       void stop() { mIsStopped = true; }
 
       // IInputStream.
-      virtual U32 read( ElementType* buffer, U32 num );
+      U32 read( ElementType* buffer, U32 num ) override;
 };
 
 //-----------------------------------------------------------------------------
@@ -299,7 +299,7 @@ class AsyncBufferedReadItem : public ThreadWorkItem
       T mElement;
 
       // WorkItem
-      virtual void execute()
+      void execute() override
       {
          if( Deref( mSourceStream ).read( &mElement, 1 ) )
          {                  
@@ -309,7 +309,7 @@ class AsyncBufferedReadItem : public ThreadWorkItem
             mAsyncStream->_onArrival( mElement );
          }
       }
-      virtual void onCancelled()
+      void onCancelled() override
       {
          Parent::onCancelled();
          destructSingle( mElement );
@@ -354,7 +354,7 @@ class AsyncSingleBufferedInputStream : public AsyncBufferedInputStream< T, Strea
    protected:
          
       // AsyncBufferedInputStream.
-      virtual void _requestNext();
+      void _requestNext() override;
 
       /// Create a new work item that reads the next element.
       virtual void _newReadItem( ThreadSafeRef< ThreadWorkItem >& outRef )

Engine/source/platform/async/asyncPacketStream.h

@@ -129,7 +129,7 @@ class AsyncPacketBufferedInputStream : public AsyncBufferedInputStream< Packet*,
             PacketType* mPacket;
 
             // WorkItem
-            virtual void execute()
+            void execute() override
             {
                Parent::execute();
                mPacket->mSizeActual += this->mNumElementsRead;
@@ -174,7 +174,7 @@ class AsyncPacketBufferedInputStream : public AsyncBufferedInputStream< Packet*,
                if( this->cancellationPoint() ) return;
                mAsyncStream->_onArrival( mPacket );
             }
-            virtual void onCancelled()
+            void onCancelled() override
             {
                Parent::onCancelled();
                destructSingle< PacketType* >( mPacket );
@@ -197,7 +197,7 @@ class AsyncPacketBufferedInputStream : public AsyncBufferedInputStream< Packet*,
       virtual PacketType* _newPacket( U32 packetSize ) { return constructSingle< PacketType* >( packetSize ); }
 
       /// Request the next packet from the underlying stream.
-      virtual void _requestNext();
+      void _requestNext() override;
 
       /// Create a new work item that reads "numElements" into "packet".
       virtual void _newReadItem( PacketReadItemRef& outRef,

Engine/source/platform/async/asyncUpdate.h

@@ -114,7 +114,7 @@ class AsyncUpdateThread : public Thread, public ThreadSafeRefCount< AsyncUpdateT
 
       virtual ~AsyncUpdateThread();
 
-      virtual void run( void* );
+      void run( void* ) override;
 
       /// Trigger the update event to notify the thread about
       /// pending updates.
@@ -141,7 +141,7 @@ class AsyncPeriodicUpdateThread : public AsyncUpdateThread
       /// Time between periodic updates in milliseconds.
       U32 mIntervalMS;
 
-      virtual void _waitForEventAndReset();
+      void _waitForEventAndReset() override;
 
    public:
 

Engine/source/platform/platformNetAsync.cpp

@@ -76,7 +76,7 @@ struct NetAsync::NameLookupWorkItem : public ThreadPool::WorkItem
    }
 
 protected:
-   virtual void execute()
+   void execute() override
    {
 	  NetAddress address;
 	  Net::Error error = Net::stringToAddress(mRequest.remoteAddr, &address, true);

Engine/source/platform/threads/threadPool.cpp

@@ -206,7 +206,7 @@ struct ThreadPool::WorkerThread : public Thread
    WorkerThread( ThreadPool* pool, U32 index );
 
    WorkerThread*     getNext();
-   virtual void      run( void* arg = 0 );
+   void      run( void* arg = 0 ) override;
 
 private:
    U32               mIndex;

Engine/source/platform/threads/threadPoolAsyncIO.h

@@ -223,7 +223,7 @@ class AsyncReadItem : public AsyncIOItem< T, Stream >
       /// elements actually read from the stream.
       U32 mNumElementsRead;
 
-      virtual void execute();
+      void execute() override;
       
       void _allocBuffer()
       {