Added microformats2 h-entry and h-card classnames

[barnabywalters]

Added microformats2 classnames into the existing markup structure to make post content machine readable and discoverable. microformats2 makes HTML content as easy to consume as JSON APIs without forcing people to publish data multiple times (DRY violation e.g. ATOM), making things such as cross-site commenting easy to build.

Vocabs:

• http://microformats.org/wiki/h-entry for posts
• http://microformats.org/wiki/h-card for author information

[JohnONolan]

microformats2 is a very interesting subject and one which we are pay close attention to. At this time though, we're not ready to recommend it as part of the default Ghost theme. We absolutely encourage you to use it in all your personal themes, however - and of course you are welcome to distribute a 'microformats2-enabled' fork of Casper!