Wildlife@Home: well that was a mess

Looks like all the spam is cleaned up now. I've set things so that if a user wants to post in our forums, they either need to have some credit, or to have gone to the wildlife video selection page and clicked on one of the watch video buttons (you won't have to actually watch one, you just need to visit the page). I'm hoping this is unique enough to confuse whatever spam script bots are out there. It also should be very easy, just two clicks so hopefully it won't keep anyone from posting whose having issues crunching work units or doing anything on wildlife@home. Let me know if you have any issues!

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