The comment DataList filter applies ParentClass = $className - when this
is the base class, it fails to recognise comments for a BlogPost. This
change uses the late class name instead.
jQuery version was extremely old, and was probably stuck at that as a way
of enabling the frivilous use of entwine on the front end for somewhat
trivial ajax submisions. A mild refactor has taken place to leverage newer
jQuery features, and remove outdated dependencies.
Also accompanying this commit are alterations to the markup to make it
more semantically correct (probably not entirely though), and help with
testing the JS functionality of reply forms (when enabled).
