RSS Feed - Parameter to ignore duplicate entries

[pvince]

Currently the "H13Door" code is broken in that the switch is constantly sending "Hey I am open!" to the logger.php page which dutifully logs each repeated "Open" ping. This then causes the RSS.php page to get duplicate events which is then having the RSS Feed flood the channel with pointless updates.

Currently it looks like the door code is behaving itself ( http://www.hive13.org/isOpen/RSS.php ) but this feature would prevent flooding for other RSS sources as well.