Fixes year to 2013 on sprints page.

REQUIRES I18N UPDATE!
Fixes year to 2013 on about page, English.
Fixes year to 2013 on sprints page, in msgid
Fixes year to 2013, sprints page msgid
Rebuilds i18n files.
Adding basic framework to support Featured Articles for sponsors.

Let me preface this by saying that this is 100% temporary ugly hacky
throwaway code that should not survive past this conference. It's a
one-off thing that lets us get the content online quickly with minimal
fuss. Do let me know if there's an equally trivial better way; but I
don't think it's worth doing "The Right Thing" here at this point.

This change adds four static templates -- one for each of our Diamond
and Gold sponsors -- and exposes them under the /sponsors/featured/ URL
tree. The sponsor names are hardcoded, as is the featured article content.

Still to do: actually expose these pages somewhere, e.g. via top-menu
dropdown, link from sponsor description, or elsewhere.
Merge pull request #115 from felixc/add-featured-sponsor-articles

Adding basic framework to support Featured Articles for sponsors.
Adds links to sponsor feature articles from the sponsorship page.
Merge pull request #116 from pyconca/sponsor-feature-links

Adds links to sponsor feature articles from the sponsorship page.
Updates i18n.
Updates schedule for Blaise, Éric, Hadrien.