Disable idle time any time inputs are locked.

This disabled the idle shutdown timer any time the user has locked the
inputs to use an external application, preventing MythTV from shutting
down and disrupting external tasks.

mythtv/libs/libmythui/mythmainwindow.cpp

@@ -2320,10 +2320,12 @@ void MythMainWindow::customEvent(QEvent *ce)
     else if (ce->type() == MythEvent::kLockInputDevicesEventType)
     {
         LockInputDevices(true);
+        PauseIdleTimer(true);
     }
     else if (ce->type() == MythEvent::kUnlockInputDevicesEventType)
     {
         LockInputDevices(false);
+        PauseIdleTimer(false);
     }
     else if (ce->type() == MythEvent::kDisableUDPListenerEventType)
     {