Fixed|Task Bar: When open, eat modifier key events

When the task bar is open, we shouldn't wake up the game by giving it
stray modifier events (e.g., when typing in the console).

doomsday/client/src/ui/widgets/taskbarwidget.cpp

@@ -540,6 +540,12 @@ bool TaskBarWidget::handleEvent(Event const &event)
         }
     }
 
+    // Don't let modifier keys fall through to the game.
+    if(isOpen() && event.isKey() && event.as<KeyEvent>().isModifier())
+    {
+        return true;
+    }
+
     if(event.type() == Event::KeyPress)
     {
         KeyEvent const &key = event.as<KeyEvent>();