Search engine crawlers have a tendency to follow versions of datagrid

pages with different column sorting, which can trigger a lot of load on

a server. While this can be partly mitigated with a robots.txt, it's

best to inform the crawler that this isn't a link it really wants to

follow.
To help avoid indexing these pages, these sorting links now have a

rel="nofollow" attribute. Most of the big crawlers support this to

some degree, though some will still crawl it regardless. Still, it

should cut down load on public servers a fair amount.

Verified the attribute on all the Review Board datagrids.