Various small fixes in file transfer related files to eliminate compilation warnings under Linux.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@563 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/rfb_win32/SFileTransferManagerWin32.h b/rfb_win32/SFileTransferManagerWin32.h
index b98de4f..ed1f997 100644
--- a/rfb_win32/SFileTransferManagerWin32.h
+++ b/rfb_win32/SFileTransferManagerWin32.h
@@ -36,8 +36,8 @@
     {
     public:
       SFileTransferManagerWin32();
-      ~SFileTransferManagerWin32();  
-      
+      virtual ~SFileTransferManagerWin32();
+
       void processDownloadMsg(MSG msg);
 
       virtual SFileTransfer *createObject(network::Socket *sock);