That irony is crawling up my back you know, I'd love to have our forums just be a git you can shoot pull requests to, but nope vBulletin isn't like that... you can write plugins/addons though, the thank button is such an addon. Have a look here http://www.vbulletin.org/forum/forumdisplay.php?f=234 for available addons, I crawled through some time ago looking for things we might like, but either unavailable or immature.