Add missing comments. (#14482, #14565)

Change-Id: I647bc8105cbcd13dd1a0c291a9df01f5f43dd65a

client/src/com/vaadin/client/ui/VPopupCalendar.java

@@ -275,7 +275,7 @@ public class VPopupCalendar extends VTextualDate implements Field,
      * setTextFieldEnabled(...) gets overridden in
      * TextualDateConnection.updateFromUIDL(...)
      * 
-     * @since
+     * @since 7.3.1
      */
     public void setTextFieldTabIndex() {
         if (BrowserInfo.get().isIE() && !textFieldEnabled) {

client/src/com/vaadin/client/ui/VUpload.java

@@ -312,6 +312,7 @@ public class VUpload extends SimplePanel {
         Scheduler.get().scheduleDeferred(startUploadCmd);
     }
 
+    /** For internal use only. May be removed or replaced in the future. */
     public void disableTitle(boolean disable) {
         if (disable) {
             // Disable title attribute for upload element.