Initial work on extended asciidoc

[lorrden]

This branch adds a number of adoc extensions:

• Typed attributes (dictionaries, arrays)
• Multiple revision lines
• Scoped attributes (attributes scoped on section)
• Paged.js rendering via adoc-based template system.

[lorrden]

Note that this does not yet fully implement the templating / page.js system. But the core extensions are in.