Addressed role of heading on h* elements

[halindrome]

As per issue #370, the generation of role="heading"
on h* elements is not actually permitted by the HTML5
Recommendation and causes problems with some assistive
technology implementations. Changed the strategy so
roles of heading are only placed on headings within notes and
issues. In order to preserve the semantic data that explicit
roles can generate via RDFa, also added RDFa markup that maps
to the implied RDFa that would have been derived from the role
values were they still present.

[halindrome]

Can you take a look at this @marcoscaceres ? I think the change is pretty clean, and I have tested the output, but I don't want to integrate it without another set of eyes.

[marcoscaceres]

LGTM

[halindrome]

Stupid question @gkellogg - given that RDFa Lite does not permit the about attribute, how would you suggest specifying the subject of these triples. The triple should be SomeFragment has a role of 'heading'. Ideas?

[gkellogg]

You're already in the chapter context, where we've generated <section class="informative" id="informative-section" typeof="bibo:Chapter" resource="#informative-section" property="bibo:hasPart">, the subject is already defined, is it not? You could then just output <span class="secno" property="xhv:role" resource="xhv:heading">. This doesn't work for #abstract, #toc, and #sotd, as they don't establish a subject, but that's probably not important.

[halindrome]

But the fragment ID for the section is NOT the fragment ID for the header element. It is for the entire section. The heading element needs its own ID. Which is trivial but it means wrapping the content of the Heading in a span so we can establish a subject and an object.

[gkellogg]

You already have a span for the scene, as I showed above, you just need a @resource definition on the containing header to establish the subject for that span.

[gkellogg]

Is there a predicate that relates the section identifier to it's header? The sections are all connected using bibo:hasPart, it would be nice to context the section to it's header.