Navigator should use a different icon while panning

The Navigator uses the same hand icon regardless whether panning
the red square or not, this branch tries to fix that, #4738
Includes a cleanup of icon names, i.e. the crosshair should not be
called the hand.

rtgui/edit.cc

@@ -1140,7 +1140,7 @@ CursorShape EditDataProvider::getCursor(int objectID)
         currSubscriber->getCursor(objectID);
     }
 
-    return CSOpenHand;
+    return CSHandOpen;
 }
 
 EditSubscriber* EditDataProvider::getCurrSubscriber()