Formula description scraper update

Now uses meta description HTML tag, which is very common. GitHub, SourceForge (sf.net/projects/<project>, not <project>.sf.net), Freecode (FreshMeat), etc. all use this tag.

Still, it does not work for some reason, but I thought I'd bring up with you guys again, since it now searches for a much more common tag. If anyone wants to finish it, please do. I'm not a good Ruby programmer.