Support extended clipboard transfers

Implements support in both client and server for the extended
clipboard format first seen in UltraVNC. Currently only implements
text handling, but that is still an improvement as it extends the
clipboard from ISO 8859-1 to full Unicode.
diff --git a/common/rfb/CConnection.h b/common/rfb/CConnection.h
index 4106a1e..f01d5d3 100644
--- a/common/rfb/CConnection.h
+++ b/common/rfb/CConnection.h
@@ -111,6 +111,15 @@
 
     virtual void serverCutText(const char* str);
 
+    virtual void handleClipboardCaps(rdr::U32 flags,
+                                     const rdr::U32* lengths);
+    virtual void handleClipboardRequest(rdr::U32 flags);
+    virtual void handleClipboardPeek(rdr::U32 flags);
+    virtual void handleClipboardNotify(rdr::U32 flags);
+    virtual void handleClipboardProvide(rdr::U32 flags,
+                                        const size_t* lengths,
+                                        const rdr::U8* const* data);
+
 
     // Methods to be overridden in a derived class
 
@@ -277,6 +286,7 @@
     DecodeManager decoder;
 
     char* serverClipboard;
+    bool hasLocalClipboard;
   };
 }
 #endif