Pass text styles downward (from parent to child)

[mojavelinux]

Currently, text styles (i.e., formatting) are applied on the traversal out of the hierarchy (in Asciidoctor::PDF::FormattedText::Transform). This means that styles are not properly inherited, and sometimes the decision about which style to apply is ambiguous. Instead, the styles should be passed downward through the hierarchy (from parent to child) so that the style on the inner-most element always wins out.

[mojavelinux]

The main issue is this line:

fragments << apply(pcdata).map {|fragment| build_fragment(fragment, tag_name, attributes) }

The inherited settings from the parent fragment need to be passed to apply so that they can be used when building the child fragments.

[mojavelinux]

The way it currently works is that the inner styles are preserved on the way out of the hierarchy, but this is not always reliable.