Look up raw gist URL via the API when a non-raw URL is pasted

People had a lot of trouble with this since it wasn't obvious that
RawGit needed the raw gist URL (and the raw gist URL couldn't be
derived locally from the non-raw URL). Hopefully this makes it easier.

One more CDN bump.

Bump CDN tag.

Unbreak copy buttons.

I'm a doofus.

Bump CDN tag.

Bump CDN tag.

Always use HTTPS URLs.

Hide inaccurate stats columns.

RawGit dev requests are now fronted by CloudFlare, so the detailed
request stats are no longer accurate.

Modernize CSS. No more Pure.

Don't allow Urls for releases