No validation has been attempted yet. Lots of changes left. This
is visibly not (very) different from the previous CSS layout. But
some simplifications have been made.
Might cause issues with local changes to themes and CSS. Also maybe
javascript which depends on certain legacy microformats elements.
The move to microformats2 is motivated by the announcement that all
microformats should be migrated to version 2, as of 2014-06-20 at:
http://microformats.org/2014/06/20/microformats-org-turns-9-upgrade-to-microformats2
