Replace "frames" with "updates" in stats

The VNC servers aren't great at getting full frames with each update,
so avoid calling it "frames per second" in the statistics as that
can be misleading.
diff --git a/vncviewer/CConn.cxx b/vncviewer/CConn.cxx
index 07e7841..d95c6ab 100644
--- a/vncviewer/CConn.cxx
+++ b/vncviewer/CConn.cxx
@@ -73,7 +73,7 @@
 
 CConn::CConn(const char* vncServerName, network::Socket* socket=NULL)
   : serverHost(0), serverPort(0), desktop(NULL),
-    frameCount(0), pixelCount(0), pendingPFChange(false),
+    updateCount(0), pixelCount(0), pendingPFChange(false),
     currentEncoding(encodingTight), lastServerEncoding((unsigned int)-1),
     formatChange(false), encodingChange(false),
     firstUpdate(true), pendingUpdate(false), continuousUpdates(false),
@@ -226,9 +226,9 @@
   return infoText;
 }
 
-unsigned CConn::getFrameCount()
+unsigned CConn::getUpdateCount()
 {
-  return frameCount;
+  return updateCount;
 }
 
 unsigned CConn::getPixelCount()
@@ -383,7 +383,7 @@
 {
   CConnection::framebufferUpdateEnd();
 
-  frameCount++;
+  updateCount++;
 
   Fl::remove_timeout(handleUpdateTimeout, this);
   desktop->updateWindow();