added gitorious.org

Added gitorious.org link after the links to Github and Bitbucket in the "use" menu.
Merge pull request #147 from blue-prawn/patch-4

added gitorious.org
companies.html: add ANSSI
Add last OUPS meetup.
Fix time format.
Sort the news in descending order (newer first).

This fixes bug #150 (consequence of a fix in ocamlrss).
Increase slightly the length for the "header" of a post.