Change links in project/usage table to point to project/usage/[uri], not project/usage/[nid]

patch looks good.

One concern about doing this. The pages this code is used on are currently cached for 1 day (but really could be cached for 1 week, since the statistics are only updated once per week). That means that if a project maintainer were to change the short_name (uri) of a project, then links from the usage statistics would return 404 errors for up to one day (or one week, if cache lifetime is increased in the future). This isn't that big of a deal, but I wonder if the benefit of having the uri in the URL outweighs the downside of the possibility that we'll be serving pages with bad links.

Yeah, that's true. I'd be in favor of restricting who can change the short name of projects.

Looks good, and much better than mine ;)

Also, +1 for caching this data for a week. I really wonder how often projects are renamed? Given the other mentioned implications, I'd say: who cares if that link does not work for 7 days at max?

I'd say it's not a huge deal if the links are dead for 7- days. Discourages people from changing their shortnames, which breaks other links as well.

This change sounds great! :)