Handlebars structure tweaks to post.handlebars

 - Combine bind-attrs on the <article> (seriously that made no sense)
 - Hoist a bind-attr class to the view, allowing more fancy styling
 - Hoist a <div> outside a conditional
 - Change href='#' to unvalued hrefs
Merge pull request #2773 from riking/post-handlebars

(Trivial) Handlebars structure tweaks to post.handlebars