Update URL of Campbell & Pedersen article

[rmzelle]

Get rid of proxied URL. Also helps with wrapping, at least in Firefox.
Per #201

[rmzelle]

@adam3smith, you can close #206 when you merge this. (I also played around a little with the CSS, but didn't get anywhere)

[adam3smith]

Someone pointed out to me that most of the other articles with a URL don't have an accessed date -- do you think it's worth adding that?

[rmzelle]

I would try to follow what's standard for most Zotero translators. If Zotero usually stores one, I agree we should add them to the metadata here.

[zuphilip]

I also played around a little with the CSS, but didn't get anywhere

You can try to add to just the url value element this CSS

word-break: break-all;

(This seems to work for me in FF and Chrome.)

[rmzelle]

@adam3smith, bump. The accessed date and wrapping issues are unrelated. No reason to not merge this in the meantime.