Added Swagger CSS-styled codeblocks

• Added Swagger CSS-styled <codeblock> elements
• Added example response support.
• Amended Markdown processing to avoid deep <topic> hierarchy
• Switched relevant <topic> elements to <section> and <example> elements
• Included metadata and <shortdesc> support.

Additional maintenance and fixes

• Update dependency on fox.jason.passthrough
• Update dependency on fox.jason.passthrough.pandoc
• Add dependency on fox.jason.extend-css