Change the label for `URL` to `Website`

[Diederik van der Boor]

Most websites use the phrase "Website" instead of "URL" in their comment forms. This is a bit more user friendly too.

[Claude Paroz]

I think that for such changes, you'll want to set up your own form class, so you are free to choose whatever form label you want. I'm not convinced of the change. Thanks for the proposal, though.