Use UTF-8 in clipboard API

In prepartion for better clipboard extensions that can send Unicode
data between the client and server.
diff --git a/common/rfb/SConnection.cxx b/common/rfb/SConnection.cxx
index 1cc330d..46f0a85 100644
--- a/common/rfb/SConnection.cxx
+++ b/common/rfb/SConnection.cxx
@@ -306,7 +306,7 @@
   strFree(clientClipboard);
   clientClipboard = NULL;
 
-  clientClipboard = strDup(str);
+  clientClipboard = latin1ToUTF8(str);
 
   handleClipboardAnnounce(true);
 }
@@ -450,7 +450,9 @@
 
 void SConnection::sendClipboardData(const char* data)
 {
-  writer()->writeServerCutText(data);
+  CharArray latin1(utf8ToLatin1(data));
+
+  writer()->writeServerCutText(latin1.buf);
 }
 
 void SConnection::writeFakeColourMap(void)